971500891 has 2 divisors, whose sum is σ = 971500892. Its totient is φ = 971500890.

The previous prime is 971500879. The next prime is 971500919. The reversal of 971500891 is 198005179.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (198005179) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-971500891 is a prime.

It is not a weakly prime, because it can be changed into another prime (971500801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485750445 + 485750446.

It is an arithmetic number, because the mean of its divisors is an integer number (485750446).

Almost surely, 2^971500891 is an apocalyptic number.

971500891 is a deficient number, since it is larger than the sum of its proper divisors (1).

971500891 is an equidigital number, since it uses as much as digits as its factorization.

971500891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 971500891 is about 31168.9090441100. The cubic root of 971500891 is about 990.4085960916.

The spelling of 971500891 in words is "nine hundred seventy-one million, five hundred thousand, eight hundred ninety-one".