20004561556 has 24 divisors (see below), whose sum is σ = 40183848320. Its totient is φ = 8535942432.

The previous prime is 20004561517. The next prime is 20004561569. The reversal of 20004561556 is 65516540002.

It is a super-2 number, since 2×20004561556² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1553520 + ... + 1566343.

Almost surely, 2^20004561556 is an apocalyptic number.

It is an amenable number.

20004561556 is an abundant number, since it is smaller than the sum of its proper divisors (20179286764).

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

20004561556 is a wasteful number, since it uses less digits than its factorization.

20004561556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3120103 (or 3120101 counting only the distinct ones).

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

The spelling of 20004561556 in words is "twenty billion, four million, five hundred sixty-one thousand, five hundred fifty-six".