21051513234 has 12 divisors (see below), whose sum is σ = 45611612046. Its totient is φ = 7017171072.

The previous prime is 21051513227. The next prime is 21051513251. The reversal of 21051513234 is 43231515012.

21051513234 is a `hidden beast` number, since 2 + 10 + 515 + 132 + 3 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12869768025 + 8181745209 = 113445^2 + 90453^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21051513198 and 21051513207.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 584764239 + ... + 584764274.

Almost surely, 2^21051513234 is an apocalyptic number.

21051513234 is an abundant number, since it is smaller than the sum of its proper divisors (24560098812).

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

21051513234 is a wasteful number, since it uses less digits than its factorization.

21051513234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1169528521 (or 1169528518 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The spelling of 21051513234 in words is "twenty-one billion, fifty-one million, five hundred thirteen thousand, two hundred thirty-four".