91137028 has 6 divisors (see below), whose sum is σ = 159489806. Its totient is φ = 45568512.

The previous prime is 91137023. The next prime is 91137041. The reversal of 91137028 is 82073119.

It can be written as a sum of positive squares in only one way, i.e., 52099524 + 39037504 = 7218^2 + 6248^2 .

It is not an unprimeable number, because it can be changed into a prime (91137023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11392125 + ... + 11392132.

Almost surely, 2^91137028 is an apocalyptic number.

It is an amenable number.

91137028 is a deficient number, since it is larger than the sum of its proper divisors (68352778).

91137028 is a wasteful number, since it uses less digits than its factorization.

91137028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22784261 (or 22784259 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 91137028 is about 9546.5715311833. The cubic root of 91137028 is about 450.0197983059.

The spelling of 91137028 in words is "ninety-one million, one hundred thirty-seven thousand, twenty-eight".