971815861 has 2 divisors, whose sum is σ = 971815862. Its totient is φ = 971815860.

The previous prime is 971815853. The next prime is 971815877. The reversal of 971815861 is 168518179.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 778744836 + 193071025 = 27906^2 + 13895^2 .

It is a cyclic number.

It is not a de Polignac number, because 971815861 - 2³ = 971815853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (971815891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485907930 + 485907931.

It is an arithmetic number, because the mean of its divisors is an integer number (485907931).

Almost surely, 2^971815861 is an apocalyptic number.

It is an amenable number.

971815861 is a deficient number, since it is larger than the sum of its proper divisors (1).

971815861 is an equidigital number, since it uses as much as digits as its factorization.

971815861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 46.

The square root of 971815861 is about 31173.9612657744. The cubic root of 971815861 is about 990.5156178803.

The spelling of 971815861 in words is "nine hundred seventy-one million, eight hundred fifteen thousand, eight hundred sixty-one".