21629992779 has 6 divisors (see below), whose sum is σ = 31243322916. Its totient is φ = 14419995180.

The previous prime is 21629992757. The next prime is 21629992799. The reversal of 21629992779 is 97729992612.

It is not a de Polignac number, because 21629992779 - 2⁷ = 21629992651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21629992799) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1201666257 + ... + 1201666274.

It is an arithmetic number, because the mean of its divisors is an integer number (5207220486).

Almost surely, 2^21629992779 is an apocalyptic number.

21629992779 is a deficient number, since it is larger than the sum of its proper divisors (9613330137).

21629992779 is a wasteful number, since it uses less digits than its factorization.

21629992779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2403332537 (or 2403332534 counting only the distinct ones).

The product of its digits is 15431472, while the sum is 63.

The spelling of 21629992779 in words is "twenty-one billion, six hundred twenty-nine million, nine hundred ninety-two thousand, seven hundred seventy-nine".