91220538 has 48 divisors (see below), whose sum is σ = 200173824. Its totient is φ = 27678720.

The previous prime is 91220537. The next prime is 91220551. The reversal of 91220538 is 83502219.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (91220537) 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 in 23 ways as a sum of consecutive naturals, for example, 52906 + ... + 54602.

It is an arithmetic number, because the mean of its divisors is an integer number (4170288).

Almost surely, 2^91220538 is an apocalyptic number.

91220538 is an abundant number, since it is smaller than the sum of its proper divisors (108953286).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91220538 is a wasteful number, since it uses less digits than its factorization.

91220538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1767 (or 1750 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 91220538 is about 9550.9443512147. The cubic root of 91220538 is about 450.1572092695.

The spelling of 91220538 in words is "ninety-one million, two hundred twenty thousand, five hundred thirty-eight".