51178820 has 96 divisors (see below), whose sum is σ = 135475200. Its totient is φ = 15776640.

The previous prime is 51178819. The next prime is 51178843. The reversal of 51178820 is 2887115.

51178820 = T₃₁₁ + T₃₁₂ + ... + T₆₉₅.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 257081 + ... + 257279.

It is an arithmetic number, because the mean of its divisors is an integer number (1411200).

Almost surely, 2^51178820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51178820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67737600).

51178820 is an abundant number, since it is smaller than the sum of its proper divisors (84296380).

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

51178820 is a wasteful number, since it uses less digits than its factorization.

51178820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 391 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 51178820 is about 7153.9373774167. The cubic root of 51178820 is about 371.2758971002.

It can be divided in two parts, 51 and 178820, that added together give a palindrome (178871).

The spelling of 51178820 in words is "fifty-one million, one hundred seventy-eight thousand, eight hundred twenty".