2157803856 has 360 divisors, whose sum is σ = 7153875456. Its totient is φ = 602795520.

The previous prime is 2157803833. The next prime is 2157803909. The reversal of 2157803856 is 6583087512.

2157803856 is a `hidden beast` number, since 21 + 578 + 0 + 3 + 8 + 56 = 666.

It is a super-2 number, since 2×2157803856² = 9312234961936937472, which contains 22 as substring.

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 71 ways as a sum of consecutive naturals, for example, 20949501 + ... + 20949603.

Almost surely, 2^2157803856 is an apocalyptic number.

2157803856 is a gapful number since it is divisible by the number (26) 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 2157803856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3576937728).

2157803856 is an abundant number, since it is smaller than the sum of its proper divisors (4996071600).

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

2157803856 is a wasteful number, since it uses less digits than its factorization.

2157803856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The square root of 2157803856 is about 46452.1673983034. The cubic root of 2157803856 is about 1292.2225683465. Note that the first 3 decimals are identical.

The spelling of 2157803856 in words is "two billion, one hundred fifty-seven million, eight hundred three thousand, eight hundred fifty-six".