91228537 has 4 divisors (see below), whose sum is σ = 92327760. Its totient is φ = 90129316.

The previous prime is 91228513. The next prime is 91228541. The reversal of 91228537 is 73582219.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91228537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91228496 and 91228505.

It is not an unprimeable number, because it can be changed into a prime (91228547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 549487 + ... + 549652.

It is an arithmetic number, because the mean of its divisors is an integer number (23081940).

Almost surely, 2^91228537 is an apocalyptic number.

It is an amenable number.

91228537 is a deficient number, since it is larger than the sum of its proper divisors (1099223).

91228537 is a wasteful number, since it uses less digits than its factorization.

91228537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099222.

The product of its digits is 30240, while the sum is 37.

The square root of 91228537 is about 9551.3630964381. The cubic root of 91228537 is about 450.1703667679.

The spelling of 91228537 in words is "ninety-one million, two hundred twenty-eight thousand, five hundred thirty-seven".