21766267938 has 16 divisors (see below), whose sum is σ = 43760457216. Its totient is φ = 7217435760.

The previous prime is 21766267921. The next prime is 21766267967. The reversal of 21766267938 is 83976266712.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9495481 + ... + 9497772.

It is an arithmetic number, because the mean of its divisors is an integer number (2735028576).

Almost surely, 2^21766267938 is an apocalyptic number.

21766267938 is an abundant number, since it is smaller than the sum of its proper divisors (21994189278).

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

21766267938 is a wasteful number, since it uses less digits than its factorization.

21766267938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18993449.

The product of its digits is 9144576, while the sum is 57.

The spelling of 21766267938 in words is "twenty-one billion, seven hundred sixty-six million, two hundred sixty-seven thousand, nine hundred thirty-eight".