91655257 has 2 divisors, whose sum is σ = 91655258. Its totient is φ = 91655256.

The previous prime is 91655243. The next prime is 91655269. The reversal of 91655257 is 75255619.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75846681 + 15808576 = 8709^2 + 3976^2 .

It is an emirp because it is prime and its reverse (75255619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91655257 - 2¹⁹ = 91130969 is a prime.

It is a super-2 number, since 2×91655257² = 16801372271472098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91655287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45827628 + 45827629.

It is an arithmetic number, because the mean of its divisors is an integer number (45827629).

Almost surely, 2^91655257 is an apocalyptic number.

It is an amenable number.

91655257 is a deficient number, since it is larger than the sum of its proper divisors (1).

91655257 is an equidigital number, since it uses as much as digits as its factorization.

91655257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94500, while the sum is 40.

The square root of 91655257 is about 9573.6752086124. The cubic root of 91655257 is about 450.8711634389.

The spelling of 91655257 in words is "ninety-one million, six hundred fifty-five thousand, two hundred fifty-seven".