331665521 has 8 divisors (see below), whose sum is σ = 371596224. Its totient is φ = 293364720.

The previous prime is 331665487. The next prime is 331665557. The reversal of 331665521 is 125566133.

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

It is a de Polignac number, because none of the positive numbers 2^k-331665521 is a prime.

It is a super-2 number, since 2×331665521² = 220004035640402882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (331665421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 407045 + ... + 407858.

It is an arithmetic number, because the mean of its divisors is an integer number (46449528).

Almost surely, 2^331665521 is an apocalyptic number.

It is an amenable number.

331665521 is a deficient number, since it is larger than the sum of its proper divisors (39930703).

331665521 is a wasteful number, since it uses less digits than its factorization.

331665521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814951.

The product of its digits is 16200, while the sum is 32.

The square root of 331665521 is about 18211.6863853955. The cubic root of 331665521 is about 692.2029438345.

The spelling of 331665521 in words is "three hundred thirty-one million, six hundred sixty-five thousand, five hundred twenty-one".