513887661 has 48 divisors (see below), whose sum is σ = 905357440. Its totient is φ = 274337280.

The previous prime is 513887659. The next prime is 513887663. The reversal of 513887661 is 166788315.

513887661 is a `hidden beast` number, since 513 + 8 + 8 + 76 + 61 = 666.

It is an interprime number because it is at equal distance from previous prime (513887659) and next prime (513887663).

It is not a de Polignac number, because 513887661 - 2¹ = 513887659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (513887663) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 84441 + ... + 90321.

Almost surely, 2^513887661 is an apocalyptic number.

It is an amenable number.

513887661 is a deficient number, since it is larger than the sum of its proper divisors (391469779).

513887661 is a wasteful number, since it uses less digits than its factorization.

513887661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5986 (or 5983 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 513887661 is about 22669.0904316869. The cubic root of 513887661 is about 800.9819509930.

It can be divided in two parts, 51388 and 7661, that added together give a 10-th power (59049 = 3¹⁰).

The spelling of 513887661 in words is "five hundred thirteen million, eight hundred eighty-seven thousand, six hundred sixty-one".