91288537 has 2 divisors, whose sum is σ = 91288538. Its totient is φ = 91288536.

The previous prime is 91288531. The next prime is 91288579. The reversal of 91288537 is 73588219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65674816 + 25613721 = 8104^2 + 5061^2 .

It is an emirp because it is prime and its reverse (73588219) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91288537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91288493 and 91288502.

It is not a weakly prime, because it can be changed into another prime (91288531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45644268 + 45644269.

It is an arithmetic number, because the mean of its divisors is an integer number (45644269).

Almost surely, 2^91288537 is an apocalyptic number.

It is an amenable number.

91288537 is a deficient number, since it is larger than the sum of its proper divisors (1).

91288537 is an equidigital number, since it uses as much as digits as its factorization.

91288537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 43.

The square root of 91288537 is about 9554.5034931178. The cubic root of 91288537 is about 450.2690358307.

The spelling of 91288537 in words is "ninety-one million, two hundred eighty-eight thousand, five hundred thirty-seven".