21010552556 has 48 divisors (see below), whose sum is σ = 42245324352. Its totient is φ = 8956569600.

The previous prime is 21010552513. The next prime is 21010552559. The reversal of 21010552556 is 65525501012.

It is not an unprimeable number, because it can be changed into a prime (21010552559) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8912930 + ... + 8915286.

It is an arithmetic number, because the mean of its divisors is an integer number (880110924).

Almost surely, 2^21010552556 is an apocalyptic number.

It is an amenable number.

21010552556 is an abundant number, since it is smaller than the sum of its proper divisors (21234771796).

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

21010552556 is a wasteful number, since it uses less digits than its factorization.

21010552556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3930 (or 3928 counting only the distinct ones).

The product of its (nonzero) digits is 15000, while the sum is 32.

The spelling of 21010552556 in words is "twenty-one billion, ten million, five hundred fifty-two thousand, five hundred fifty-six".