21673207506 has 32 divisors (see below), whose sum is σ = 45283811328. Its totient is φ = 6907119120.

The previous prime is 21673207481. The next prime is 21673207511. The reversal of 21673207506 is 60570237612.

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, 686506 + ... + 717381.

It is an arithmetic number, because the mean of its divisors is an integer number (1415119104).

Almost surely, 2^21673207506 is an apocalyptic number.

21673207506 is an abundant number, since it is smaller than the sum of its proper divisors (23610603822).

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

21673207506 is a wasteful number, since it uses less digits than its factorization.

21673207506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1404006.

The product of its (nonzero) digits is 105840, while the sum is 39.

The spelling of 21673207506 in words is "twenty-one billion, six hundred seventy-three million, two hundred seven thousand, five hundred six".