21232475556 has 12 divisors (see below), whose sum is σ = 49542442992. Its totient is φ = 7077491848.

The previous prime is 21232475519. The next prime is 21232475573. The reversal of 21232475556 is 65557423212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21232475556² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884686470 + ... + 884686493.

It is an arithmetic number, because the mean of its divisors is an integer number (4128536916).

Almost surely, 2^21232475556 is an apocalyptic number.

It is an amenable number.

21232475556 is an abundant number, since it is smaller than the sum of its proper divisors (28309967436).

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

21232475556 is a wasteful number, since it uses less digits than its factorization.

21232475556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769372970 (or 1769372968 counting only the distinct ones).

The product of its digits is 504000, while the sum is 42.

Adding to 21232475556 its reverse (65557423212), we get a palindrome (86789898768).

The spelling of 21232475556 in words is "twenty-one billion, two hundred thirty-two million, four hundred seventy-five thousand, five hundred fifty-six".