91205213 has 16 divisors (see below), whose sum is σ = 101122560. Its totient is φ = 81572400.

The previous prime is 91205207. The next prime is 91205227. The reversal of 91205213 is 31250219.

It is a cyclic number.

It is not a de Polignac number, because 91205213 - 2¹⁶ = 91139677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91205243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 240458 + ... + 240836.

It is an arithmetic number, because the mean of its divisors is an integer number (6320160).

Almost surely, 2^91205213 is an apocalyptic number.

It is an amenable number.

91205213 is a deficient number, since it is larger than the sum of its proper divisors (9917347).

91205213 is a wasteful number, since it uses less digits than its factorization.

91205213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 91205213 is about 9550.1420408285. The cubic root of 91205213 is about 450.1319991368.

The spelling of 91205213 in words is "ninety-one million, two hundred five thousand, two hundred thirteen".