97931521 has 4 divisors (see below), whose sum is σ = 101308500. Its totient is φ = 94554544.

The previous prime is 97931501. The next prime is 97931527. The reversal of 97931521 is 12513979.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12513979 = 41 ⋅305219.

It can be written as a sum of positive squares in 2 ways, for example, as 36481600 + 61449921 = 6040^2 + 7839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-97931521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (97931527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1688446 + ... + 1688503.

It is an arithmetic number, because the mean of its divisors is an integer number (25327125).

Almost surely, 2^97931521 is an apocalyptic number.

It is an amenable number.

97931521 is a deficient number, since it is larger than the sum of its proper divisors (3376979).

97931521 is a wasteful number, since it uses less digits than its factorization.

97931521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3376978.

The product of its digits is 17010, while the sum is 37.

The square root of 97931521 is about 9896.0356203886. The cubic root of 97931521 is about 460.9362170858.

The spelling of 97931521 in words is "ninety-seven million, nine hundred thirty-one thousand, five hundred twenty-one".