21671679953 has 24 divisors (see below), whose sum is σ = 27343055040. Its totient is φ = 16813130400.

The previous prime is 21671679947. The next prime is 21671680039. The reversal of 21671679953 is 35997617612.

It is not a de Polignac number, because 21671679953 - 2⁴ = 21671679937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21671679853) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138098 + ... + 249828.

It is an arithmetic number, because the mean of its divisors is an integer number (1139293960).

Almost surely, 2^21671679953 is an apocalyptic number.

It is an amenable number.

21671679953 is a deficient number, since it is larger than the sum of its proper divisors (5671375087).

21671679953 is a wasteful number, since it uses less digits than its factorization.

21671679953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111989 (or 111978 counting only the distinct ones).

The product of its digits is 4286520, while the sum is 56.

The spelling of 21671679953 in words is "twenty-one billion, six hundred seventy-one million, six hundred seventy-nine thousand, nine hundred fifty-three".