21516847494 has 32 divisors (see below), whose sum is σ = 43629191136. Its totient is φ = 7073587200.

The previous prime is 21516847481. The next prime is 21516847523. The reversal of 21516847494 is 49474861512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86664 + ... + 224820.

It is an arithmetic number, because the mean of its divisors is an integer number (1363412223).

Almost surely, 2^21516847494 is an apocalyptic number.

21516847494 is an abundant number, since it is smaller than the sum of its proper divisors (22112343642).

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

21516847494 is a wasteful number, since it uses less digits than its factorization.

21516847494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138520.

The product of its digits is 1935360, while the sum is 51.

The spelling of 21516847494 in words is "twenty-one billion, five hundred sixteen million, eight hundred forty-seven thousand, four hundred ninety-four".