91049521 has 4 divisors (see below), whose sum is σ = 91091952. Its totient is φ = 91007092.

The previous prime is 91049513. The next prime is 91049537. The reversal of 91049521 is 12594019.

It is the 3896-th star number.

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 not a de Polignac number, because 91049521 - 2³ = 91049513 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91049551) 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, 17815 + ... + 22348.

It is an arithmetic number, because the mean of its divisors is an integer number (22772988).

Almost surely, 2^91049521 is an apocalyptic number.

It is an amenable number.

91049521 is a deficient number, since it is larger than the sum of its proper divisors (42431).

91049521 is a wasteful number, since it uses less digits than its factorization.

91049521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42430.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 91049521 is about 9541.9872668119. The cubic root of 91049521 is about 449.8757204125.

The spelling of 91049521 in words is "ninety-one million, forty-nine thousand, five hundred twenty-one".