971664431 has 2 divisors, whose sum is σ = 971664432. Its totient is φ = 971664430.

The previous prime is 971664413. The next prime is 971664439. The reversal of 971664431 is 134466179.

Together with previous prime (971664413) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (134466179) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-971664431 is a prime.

It is a super-2 number, since 2×971664431² = 1888263532941107522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (971664439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485832215 + 485832216.

It is an arithmetic number, because the mean of its divisors is an integer number (485832216).

Almost surely, 2^971664431 is an apocalyptic number.

971664431 is a deficient number, since it is larger than the sum of its proper divisors (1).

971664431 is an equidigital number, since it uses as much as digits as its factorization.

971664431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 41.

The square root of 971664431 is about 31171.5323813251. The cubic root of 971664431 is about 990.4641672652.

It can be divided in two parts, 9716 and 64431, that added together give a palindrome (74147).

The spelling of 971664431 in words is "nine hundred seventy-one million, six hundred sixty-four thousand, four hundred thirty-one".