1990656 has 84 divisors (see below), whose sum is σ = 5963412. Its totient is φ = 663552.

The previous prime is 1990643. The next prime is 1990657. The reversal of 1990656 is 6560991.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a Jordan-Polya number, since it can be written as (4!)⁴ ⋅ 3!.

It is a super-2 number, since 2×1990656² = 7925422620672, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 12.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 1990656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990657) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 663551 + 663552 + 663553.

It is an arithmetic number, because the mean of its divisors is an integer number (70993).

2^1990656 is an apocalyptic number.

1990656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1990656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2981706).

1990656 is an abundant number, since it is smaller than the sum of its proper divisors (3972756).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1990656 is an frugal number, since it uses more digits than its factorization.

1990656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41 (or 5 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 1990656 is about 1410.9060918431. The cubic root of 1990656 is about 125.7955869220.

The spelling of 1990656 in words is "one million, nine hundred ninety thousand, six hundred fifty-six".