21372755619431 has 2 divisors, whose sum is σ = 21372755619432. Its totient is φ = 21372755619430.

The previous prime is 21372755619427. The next prime is 21372755619473. The reversal of 21372755619431 is 13491655727312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21372755619431 - 2² = 21372755619427 is a prime.

It is a super-2 number, since 2×21372755619431² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21372755619731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10686377809715 + 10686377809716.

It is an arithmetic number, because the mean of its divisors is an integer number (10686377809716).

Almost surely, 2^{21372755619431} is an apocalyptic number.

21372755619431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21372755619431 is an equidigital number, since it uses as much as digits as its factorization.

21372755619431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9525600, while the sum is 56.

The spelling of 21372755619431 in words is "twenty-one trillion, three hundred seventy-two billion, seven hundred fifty-five million, six hundred nineteen thousand, four hundred thirty-one".