51810561 has 24 divisors (see below), whose sum is σ = 81872544. Its totient is φ = 31311360.

The previous prime is 51810553. The next prime is 51810569. The reversal of 51810561 is 16501815.

It is an interprime number because it is at equal distance from previous prime (51810553) and next prime (51810569).

It is not a de Polignac number, because 51810561 - 2³ = 51810553 is a prime.

It is a super-2 number, since 2×51810561² = 5368668462269442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51810569) 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, 56670 + ... + 57576.

It is an arithmetic number, because the mean of its divisors is an integer number (3411356).

Almost surely, 2^51810561 is an apocalyptic number.

It is an amenable number.

51810561 is a deficient number, since it is larger than the sum of its proper divisors (30061983).

51810561 is a wasteful number, since it uses less digits than its factorization.

51810561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1501 (or 1498 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 27.

The square root of 51810561 is about 7197.9553346766. The cubic root of 51810561 is about 372.7973057001.

The spelling of 51810561 in words is "fifty-one million, eight hundred ten thousand, five hundred sixty-one".