19640813831 has 2 divisors, whose sum is σ = 19640813832. Its totient is φ = 19640813830.

The previous prime is 19640813783. The next prime is 19640813833. The reversal of 19640813831 is 13831804691.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19640813831 - 2⁶ = 19640813767 is a prime.

It is a super-2 number, since 2×19640813831² (a number of 21 digits) contains 22 as substring.

Together with 19640813833, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19640813833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9820406915 + 9820406916.

It is an arithmetic number, because the mean of its divisors is an integer number (9820406916).

Almost surely, 2^19640813831 is an apocalyptic number.

19640813831 is a deficient number, since it is larger than the sum of its proper divisors (1).

19640813831 is an equidigital number, since it uses as much as digits as its factorization.

19640813831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 44.

The spelling of 19640813831 in words is "nineteen billion, six hundred forty million, eight hundred thirteen thousand, eight hundred thirty-one".