1656991040 has 56 divisors (see below), whose sum is σ = 3963265632. Its totient is φ = 659847680.

The previous prime is 1656991027. The next prime is 1656991079. The reversal of 1656991040 is 401996561.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61235 + ... + 84045.

Almost surely, 2^1656991040 is an apocalyptic number.

1656991040 is a gapful number since it is divisible by the number (10) 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 1656991040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1981632816).

1656991040 is an abundant number, since it is smaller than the sum of its proper divisors (2306274592).

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

1656991040 is a wasteful number, since it uses less digits than its factorization.

1656991040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23055 (or 23045 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 1656991040 is about 40706.1548171772. The cubic root of 1656991040 is about 1183.3323024964.

The spelling of 1656991040 in words is "one billion, six hundred fifty-six million, nine hundred ninety-one thousand, forty".