21134426172 has 12 divisors (see below), whose sum is σ = 49313661096. Its totient is φ = 7044808720.

The previous prime is 21134426143. The next prime is 21134426191. The reversal of 21134426172 is 27162443112.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880601079 + ... + 880601102.

It is an arithmetic number, because the mean of its divisors is an integer number (4109471758).

Almost surely, 2^21134426172 is an apocalyptic number.

It is an amenable number.

21134426172 is an abundant number, since it is smaller than the sum of its proper divisors (28179234924).

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

21134426172 is a wasteful number, since it uses less digits than its factorization.

21134426172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1761202188 (or 1761202186 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

Adding to 21134426172 its reverse (27162443112), we get a palindrome (48296869284).

The spelling of 21134426172 in words is "twenty-one billion, one hundred thirty-four million, four hundred twenty-six thousand, one hundred seventy-two".