331672721 has 12 divisors (see below), whose sum is σ = 353301300. Its totient is φ = 311296608.

The previous prime is 331672711. The next prime is 331672729. The reversal of 331672721 is 127276133.

It can be written as a sum of positive squares in 2 ways, for example, as 138768400 + 192904321 = 11780^2 + 13889^2 .

It is not a de Polignac number, because 331672721 - 2¹⁴ = 331656337 is a prime.

It is a super-2 number, since 2×331672721² = 220013587711087682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (331672729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35135 + ... + 43563.

It is an arithmetic number, because the mean of its divisors is an integer number (29441775).

Almost surely, 2^331672721 is an apocalyptic number.

It is an amenable number.

331672721 is a deficient number, since it is larger than the sum of its proper divisors (21628579).

331672721 is a wasteful number, since it uses less digits than its factorization.

331672721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8576 (or 8557 counting only the distinct ones).

The product of its digits is 10584, while the sum is 32.

The square root of 331672721 is about 18211.8840595914. The cubic root of 331672721 is about 692.2079527213.

The spelling of 331672721 in words is "three hundred thirty-one million, six hundred seventy-two thousand, seven hundred twenty-one".