21864374931 has 32 divisors (see below), whose sum is σ = 34807127040. Its totient is φ = 11936479104.

The previous prime is 21864374921. The next prime is 21864374941. The reversal of 21864374931 is 13947346812.

It is an interprime number because it is at equal distance from previous prime (21864374921) and next prime (21864374941).

It is not a de Polignac number, because 21864374931 - 2¹¹ = 21864372883 is a prime.

It is a super-2 number, since 2×21864374931² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21864374911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 385465 + ... + 438533.

It is an arithmetic number, because the mean of its divisors is an integer number (1087722720).

Almost surely, 2^21864374931 is an apocalyptic number.

21864374931 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21864374931 is a deficient number, since it is larger than the sum of its proper divisors (12942752109).

21864374931 is a wasteful number, since it uses less digits than its factorization.

21864374931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53955.

The product of its digits is 870912, while the sum is 48.

The spelling of 21864374931 in words is "twenty-one billion, eight hundred sixty-four million, three hundred seventy-four thousand, nine hundred thirty-one".