91566506 has 4 divisors (see below), whose sum is σ = 137349762. Its totient is φ = 45783252.

The previous prime is 91566469. The next prime is 91566509. The reversal of 91566506 is 60566519.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60566519 = 13 ⋅4658963.

It can be written as a sum of positive squares in only one way, i.e., 61481281 + 30085225 = 7841^2 + 5485^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 91566506.

It is not an unprimeable number, because it can be changed into a prime (91566509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22891625 + ... + 22891628.

Almost surely, 2^91566506 is an apocalyptic number.

91566506 is a deficient number, since it is larger than the sum of its proper divisors (45783256).

91566506 is a wasteful number, since it uses less digits than its factorization.

91566506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45783255.

The product of its (nonzero) digits is 48600, while the sum is 38.

The square root of 91566506 is about 9569.0389277085. The cubic root of 91566506 is about 450.7255882671.

The spelling of 91566506 in words is "ninety-one million, five hundred sixty-six thousand, five hundred six".