91523857 has 2 divisors, whose sum is σ = 91523858. Its totient is φ = 91523856.

The previous prime is 91523837. The next prime is 91523863. The reversal of 91523857 is 75832519.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88341201 + 3182656 = 9399^2 + 1784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91523857 is a prime.

It is not a weakly prime, because it can be changed into another prime (91523837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45761928 + 45761929.

It is an arithmetic number, because the mean of its divisors is an integer number (45761929).

Almost surely, 2^91523857 is an apocalyptic number.

It is an amenable number.

91523857 is a deficient number, since it is larger than the sum of its proper divisors (1).

91523857 is an equidigital number, since it uses as much as digits as its factorization.

91523857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 40.

The square root of 91523857 is about 9566.8101789468. The cubic root of 91523857 is about 450.6555991348.

The spelling of 91523857 in words is "ninety-one million, five hundred twenty-three thousand, eight hundred fifty-seven".