21253134216 has 16 divisors (see below), whose sum is σ = 53132835600. Its totient is φ = 7084378064.

The previous prime is 21253134181. The next prime is 21253134223. The reversal of 21253134216 is 61243135212.

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, 442773606 + ... + 442773653.

It is an arithmetic number, because the mean of its divisors is an integer number (3320802225).

Almost surely, 2^21253134216 is an apocalyptic number.

It is an amenable number.

21253134216 is an abundant number, since it is smaller than the sum of its proper divisors (31879701384).

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

21253134216 is a wasteful number, since it uses less digits than its factorization.

21253134216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 885547268 (or 885547264 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

Adding to 21253134216 its reverse (61243135212), we get a palindrome (82496269428).

The spelling of 21253134216 in words is "twenty-one billion, two hundred fifty-three million, one hundred thirty-four thousand, two hundred sixteen".