201312531 has 24 divisors (see below), whose sum is σ = 339112800. Its totient is φ = 115033968.

The previous prime is 201312499. The next prime is 201312563. The reversal of 201312531 is 135213102.

201312531 is a `hidden beast` number, since 2 + 0 + 131 + 2 + 531 = 666.

It is an interprime number because it is at equal distance from previous prime (201312499) and next prime (201312563).

It is not a de Polignac number, because 201312531 - 2⁵ = 201312499 is a prime.

It is a super-2 number, since 2×201312531² = 81053470275251922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (201312131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29520 + ... + 35693.

It is an arithmetic number, because the mean of its divisors is an integer number (14129700).

Almost surely, 2^201312531 is an apocalyptic number.

201312531 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

201312531 is a deficient number, since it is larger than the sum of its proper divisors (137800269).

201312531 is an equidigital number, since it uses as much as digits as its factorization.

201312531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65240 (or 65223 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 201312531 is about 14188.4647160995. The cubic root of 201312531 is about 586.0800472681.

Adding to 201312531 its reverse (135213102), we get a palindrome (336525633).

The spelling of 201312531 in words is "two hundred one million, three hundred twelve thousand, five hundred thirty-one".