513655681 has 12 divisors (see below), whose sum is σ = 651838320. Its totient is φ = 400250760.

The previous prime is 513655673. The next prime is 513655729. The reversal of 513655681 is 186556315.

It is not a de Polignac number, because 513655681 - 2³ = 513655673 is a prime.

It is a super-2 number, since 2×513655681² = 527684317247147522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (513655601) 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, 475951 + ... + 477028.

It is an arithmetic number, because the mean of its divisors is an integer number (54319860).

Almost surely, 2^513655681 is an apocalyptic number.

It is an amenable number.

513655681 is a deficient number, since it is larger than the sum of its proper divisors (138182639).

513655681 is a wasteful number, since it uses less digits than its factorization.

513655681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953004 (or 952997 counting only the distinct ones).

The product of its digits is 108000, while the sum is 40.

The square root of 513655681 is about 22663.9731953601. The cubic root of 513655681 is about 800.8614059959.

The spelling of 513655681 in words is "five hundred thirteen million, six hundred fifty-five thousand, six hundred eighty-one".