2001556456 has 32 divisors (see below), whose sum is σ = 3828746880. Its totient is φ = 980728000.

The previous prime is 2001556451. The next prime is 2001556471. The reversal of 2001556456 is 6546551002.

It is a super-3 number, since 3×2001556456³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (2001556451) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84306 + ... + 105406.

It is an arithmetic number, because the mean of its divisors is an integer number (119648340).

Almost surely, 2^2001556456 is an apocalyptic number.

It is an amenable number.

2001556456 is a deficient number, since it is larger than the sum of its proper divisors (1827190424).

2001556456 is a wasteful number, since it uses less digits than its factorization.

2001556456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21345 (or 21341 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 34.

The square root of 2001556456 is about 44738.7578727886. The cubic root of 2001556456 is about 1260.2478004270.

The spelling of 2001556456 in words is "two billion, one million, five hundred fifty-six thousand, four hundred fifty-six".