21799813297931 has 4 divisors (see below), whose sum is σ = 21874215391392. Its totient is φ = 21725411204472.

The previous prime is 21799813297901. The next prime is 21799813297949. The reversal of 21799813297931 is 13979231899712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21799813297931 - 2¹⁰ = 21799813296907 is a prime.

It is a super-2 number, since 2×21799813297931² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21799813297901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37201046291 + ... + 37201046876.

It is an arithmetic number, because the mean of its divisors is an integer number (5468553847848).

Almost surely, 2^{21799813297931} is an apocalyptic number.

21799813297931 is a deficient number, since it is larger than the sum of its proper divisors (74402093461).

21799813297931 is an equidigital number, since it uses as much as digits as its factorization.

21799813297931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74402093460.

The product of its digits is 92588832, while the sum is 71.

The spelling of 21799813297931 in words is "twenty-one trillion, seven hundred ninety-nine billion, eight hundred thirteen million, two hundred ninety-seven thousand, nine hundred thirty-one".