97891961 has 2 divisors, whose sum is σ = 97891962. Its totient is φ = 97891960.

The previous prime is 97891939. The next prime is 97891987. The reversal of 97891961 is 16919879.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80209936 + 17682025 = 8956^2 + 4205^2 .

It is a cyclic number.

It is not a de Polignac number, because 97891961 - 2¹⁸ = 97629817 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (97891931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48945980 + 48945981.

It is an arithmetic number, because the mean of its divisors is an integer number (48945981).

Almost surely, 2^97891961 is an apocalyptic number.

It is an amenable number.

97891961 is a deficient number, since it is larger than the sum of its proper divisors (1).

97891961 is an equidigital number, since it uses as much as digits as its factorization.

97891961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 50.

The square root of 97891961 is about 9894.0366382988. The cubic root of 97891961 is about 460.8741427831.

The spelling of 97891961 in words is "ninety-seven million, eight hundred ninety-one thousand, nine hundred sixty-one".