513631881 has 16 divisors (see below), whose sum is σ = 869641600. Its totient is φ = 293503824.

The previous prime is 513631879. The next prime is 513631903. The reversal of 513631881 is 188136315.

513631881 is a `hidden beast` number, since 5 + 13 + 631 + 8 + 8 + 1 = 666.

It is not a de Polignac number, because 513631881 - 2¹ = 513631879 is a prime.

It is a super-2 number, since 2×513631881² = 527635418359196322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (513631801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1358626 + ... + 1359003.

It is an arithmetic number, because the mean of its divisors is an integer number (54352600).

Almost surely, 2^513631881 is an apocalyptic number.

It is an amenable number.

513631881 is a deficient number, since it is larger than the sum of its proper divisors (356009719).

513631881 is a wasteful number, since it uses less digits than its factorization.

513631881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2717645 (or 2717639 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 513631881 is about 22663.4481268848. The cubic root of 513631881 is about 800.8490366231.

The spelling of 513631881 in words is "five hundred thirteen million, six hundred thirty-one thousand, eight hundred eighty-one".