97261991 has 2 divisors, whose sum is σ = 97261992. Its totient is φ = 97261990.

The previous prime is 97261961. The next prime is 97262003. The reversal of 97261991 is 19916279.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 97261991 - 2²² = 93067687 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97261921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48630995 + 48630996.

It is an arithmetic number, because the mean of its divisors is an integer number (48630996).

Almost surely, 2^97261991 is an apocalyptic number.

97261991 is a deficient number, since it is larger than the sum of its proper divisors (1).

97261991 is an equidigital number, since it uses as much as digits as its factorization.

97261991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61236, while the sum is 44.

The square root of 97261991 is about 9862.1494107522. The cubic root of 97261991 is about 459.8833841125.

The spelling of 97261991 in words is "ninety-seven million, two hundred sixty-one thousand, nine hundred ninety-one".