51817860 has 48 divisors (see below), whose sum is σ = 161212800. Its totient is φ = 13817952.

The previous prime is 51817849. The next prime is 51817861. The reversal of 51817860 is 6871815.

It is a super-2 number, since 2×51817860² = 5370181229959200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (51817861) 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, 47440 + ... + 48519.

It is an arithmetic number, because the mean of its divisors is an integer number (3358600).

Almost surely, 2^51817860 is an apocalyptic number.

It is an amenable number.

51817860 is an abundant number, since it is smaller than the sum of its proper divisors (109394940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51817860 is a wasteful number, since it uses less digits than its factorization.

51817860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95977 (or 95969 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

The square root of 51817860 is about 7198.4623358048. The cubic root of 51817860 is about 372.8148112672.

It can be divided in two parts, 5181 and 7860, that added together give a triangular number (13041 = T₁₆₁).

The spelling of 51817860 in words is "fifty-one million, eight hundred seventeen thousand, eight hundred sixty".