51156840 has 64 divisors (see below), whose sum is σ = 175397760. Its totient is φ = 11692800.

The previous prime is 51156839. The next prime is 51156863. The reversal of 51156840 is 4865115.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 51156798 and 51156807.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29611 + ... + 31290.

It is an arithmetic number, because the mean of its divisors is an integer number (2740590).

Almost surely, 2^51156840 is an apocalyptic number.

It is an amenable number.

51156840 is an abundant number, since it is smaller than the sum of its proper divisors (124240920).

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

51156840 is a wasteful number, since it uses less digits than its factorization.

51156840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60922 (or 60918 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 51156840 is about 7152.4009954700. The cubic root of 51156840 is about 371.2227383081. Note that the first 3 decimals are identical.

The spelling of 51156840 in words is "fifty-one million, one hundred fifty-six thousand, eight hundred forty".