1320531661931 has 2 divisors, whose sum is σ = 1320531661932. Its totient is φ = 1320531661930.

The previous prime is 1320531661919. The next prime is 1320531661949. The reversal of 1320531661931 is 1391661350231.

It is a weak prime.

It is an emirp because it is prime and its reverse (1391661350231) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320531661931 is a prime.

It is a super-2 number, since 2×1320531661931² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1320531661951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660265830965 + 660265830966.

It is an arithmetic number, because the mean of its divisors is an integer number (660265830966).

Almost surely, 2^{1320531661931} is an apocalyptic number.

1320531661931 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320531661931 is an equidigital number, since it uses as much as digits as its factorization.

1320531661931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 41.

The spelling of 1320531661931 in words is "one trillion, three hundred twenty billion, five hundred thirty-one million, six hundred sixty-one thousand, nine hundred thirty-one".