51626778 has 16 divisors (see below), whose sum is σ = 118004160. Its totient is φ = 14750496.

The previous prime is 51626767. The next prime is 51626797. The reversal of 51626778 is 87762615.

It is a super-2 number, since 2×51626778² = 5330648413322568, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 1229209 = 51626778 / (5 + 1 + 6 + 2 + 6 + 7 + 7 + 8).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 614563 + ... + 614646.

It is an arithmetic number, because the mean of its divisors is an integer number (7375260).

Almost surely, 2^51626778 is an apocalyptic number.

51626778 is an abundant number, since it is smaller than the sum of its proper divisors (66377382).

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

51626778 is a wasteful number, since it uses less digits than its factorization.

51626778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1229221.

The product of its digits is 141120, while the sum is 42.

The square root of 51626778 is about 7185.1776595990. The cubic root of 51626778 is about 372.3559865500.

The spelling of 51626778 in words is "fifty-one million, six hundred twenty-six thousand, seven hundred seventy-eight".