91204540 has 24 divisors (see below), whose sum is σ = 218891232. Its totient is φ = 31270080.

The previous prime is 91204537. The next prime is 91204549. The reversal of 91204540 is 4540219.

It is a super-2 number, since 2×91204540² = 16636536233223200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91204549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 325591 + ... + 325870.

It is an arithmetic number, because the mean of its divisors is an integer number (9120468).

Almost surely, 2^91204540 is an apocalyptic number.

It is an amenable number.

91204540 is an abundant number, since it is smaller than the sum of its proper divisors (127686692).

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

91204540 is a wasteful number, since it uses less digits than its factorization.

91204540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651477 (or 651475 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 91204540 is about 9550.1068056855. The cubic root of 91204540 is about 450.1308919648.

Adding to 91204540 its reverse (4540219), we get a palindrome (95744759).

The spelling of 91204540 in words is "ninety-one million, two hundred four thousand, five hundred forty".