516661561 has 12 divisors (see below), whose sum is σ = 565019820. Its totient is φ = 472180800.

The previous prime is 516661549. The next prime is 516661573. The reversal of 516661561 is 165166615.

It is an interprime number because it is at equal distance from previous prime (516661549) and next prime (516661573).

It can be written as a sum of positive squares in 6 ways, for example, as 3367225 + 513294336 = 1835^2 + 22656^2 .

It is not a de Polignac number, because 516661561 - 2¹¹ = 516659513 is a prime.

It is a super-2 number, since 2×516661561² = 533878337229913442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 516661561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (516661261) 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, 1935 + ... + 32203.

It is an arithmetic number, because the mean of its divisors is an integer number (47084985).

Almost surely, 2^516661561 is an apocalyptic number.

It is an amenable number.

516661561 is a deficient number, since it is larger than the sum of its proper divisors (48358259).

516661561 is a wasteful number, since it uses less digits than its factorization.

516661561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30396 (or 30383 counting only the distinct ones).

The product of its digits is 32400, while the sum is 37.

The square root of 516661561 is about 22730.1905183393. The cubic root of 516661561 is about 802.4205650485.

The spelling of 516661561 in words is "five hundred sixteen million, six hundred sixty-one thousand, five hundred sixty-one".