1997856 has 72 divisors (see below), whose sum is σ = 6499584. Its totient is φ = 570240.

The previous prime is 1997851. The next prime is 1997867. The reversal of 1997856 is 6587991.

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (1997851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1521 + ... + 2511.

It is an arithmetic number, because the mean of its divisors is an integer number (90272).

2^1997856 is an apocalyptic number.

1997856 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 1997856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3249792).

1997856 is an abundant number, since it is smaller than the sum of its proper divisors (4501728).

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

1997856 is a wasteful number, since it uses less digits than its factorization.

1997856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1014 (or 1003 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 1997856 is about 1413.4553406458. The cubic root of 1997856 is about 125.9470677135.

The spelling of 1997856 in words is "one million, nine hundred ninety-seven thousand, eight hundred fifty-six".