91521553 has 8 divisors (see below), whose sum is σ = 94381056. Its totient is φ = 88692000.

The previous prime is 91521541. The next prime is 91521559. The reversal of 91521553 is 35512519.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91521553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91521559) 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, 1201 + ... + 13582.

It is an arithmetic number, because the mean of its divisors is an integer number (11797632).

Almost surely, 2^91521553 is an apocalyptic number.

It is an amenable number.

91521553 is a deficient number, since it is larger than the sum of its proper divisors (2859503).

91521553 is a wasteful number, since it uses less digits than its factorization.

91521553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14975.

The product of its digits is 6750, while the sum is 31.

The square root of 91521553 is about 9566.6897618769. The cubic root of 91521553 is about 450.6518175372.

The spelling of 91521553 in words is "ninety-one million, five hundred twenty-one thousand, five hundred fifty-three".