331731213 has 32 divisors (see below), whose sum is σ = 491443200. Its totient is φ = 197366400.

The previous prime is 331731157. The next prime is 331731221. The reversal of 331731213 is 312137133.

It is not a de Polignac number, because 331731213 - 2²¹ = 329634061 is a prime.

It is a super-2 number, since 2×331731213² = 220091195356902738, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331731223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 525408 + ... + 526038.

It is an arithmetic number, because the mean of its divisors is an integer number (15357600).

Almost surely, 2^331731213 is an apocalyptic number.

331731213 is a gapful number since it is divisible by the number (33) formed by its first and last digit.

It is an amenable number.

331731213 is a deficient number, since it is larger than the sum of its proper divisors (159711987).

331731213 is a wasteful number, since it uses less digits than its factorization.

331731213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913.

The product of its digits is 1134, while the sum is 24.

The square root of 331731213 is about 18213.4898632854. The cubic root of 331731213 is about 692.2486416747.

Adding to 331731213 its reverse (312137133), we get a palindrome (643868346).

The spelling of 331731213 in words is "three hundred thirty-one million, seven hundred thirty-one thousand, two hundred thirteen".