21512414451431 has 16 divisors (see below), whose sum is σ = 22931683891200. Its totient is φ = 20121857634528.

The previous prime is 21512414451403. The next prime is 21512414451461. The reversal of 21512414451431 is 13415441421512.

It is a cyclic number.

It is not a de Polignac number, because 21512414451431 - 2²² = 21512410257127 is a prime.

It is a super-2 number, since 2×21512414451431² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512414451461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138634370 + ... + 138789456.

It is an arithmetic number, because the mean of its divisors is an integer number (1433230243200).

Almost surely, 2^{21512414451431} is an apocalyptic number.

21512414451431 is a deficient number, since it is larger than the sum of its proper divisors (1419269439769).

21512414451431 is a wasteful number, since it uses less digits than its factorization.

21512414451431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247598.

The product of its digits is 76800, while the sum is 38.

Adding to 21512414451431 its reverse (13415441421512), we get a palindrome (34927855872943).

The spelling of 21512414451431 in words is "twenty-one trillion, five hundred twelve billion, four hundred fourteen million, four hundred fifty-one thousand, four hundred thirty-one".