91712857 has 2 divisors, whose sum is σ = 91712858. Its totient is φ = 91712856.

The previous prime is 91712837. The next prime is 91712861. The reversal of 91712857 is 75821719.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83978896 + 7733961 = 9164^2 + 2781^2 .

It is a cyclic number.

It is not a de Polignac number, because 91712857 - 2¹⁹ = 91188569 is a prime.

It is a super-2 number, since 2×91712857² = 16822496278204898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91712827) 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, 45856428 + 45856429.

It is an arithmetic number, because the mean of its divisors is an integer number (45856429).

Almost surely, 2^91712857 is an apocalyptic number.

It is an amenable number.

91712857 is a deficient number, since it is larger than the sum of its proper divisors (1).

91712857 is an equidigital number, since it uses as much as digits as its factorization.

91712857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 40.

The square root of 91712857 is about 9576.6829852512. The cubic root of 91712857 is about 450.9655924311.

The spelling of 91712857 in words is "ninety-one million, seven hundred twelve thousand, eight hundred fifty-seven".