51437778 has 16 divisors (see below), whose sum is σ = 117572160. Its totient is φ = 14696496.

The previous prime is 51437741. The next prime is 51437831. The reversal of 51437778 is 87773415.

It is a happy number.

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: 1224709 = 51437778 / (5 + 1 + 4 + 3 + 7 + 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, 612313 + ... + 612396.

It is an arithmetic number, because the mean of its divisors is an integer number (7348260).

Almost surely, 2^51437778 is an apocalyptic number.

51437778 is an abundant number, since it is smaller than the sum of its proper divisors (66134382).

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

51437778 is a wasteful number, since it uses less digits than its factorization.

51437778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1224721.

The product of its digits is 164640, while the sum is 42.

The square root of 51437778 is about 7172.0135248060. The cubic root of 51437778 is about 371.9010460584.

It can be divided in two parts, 5143 and 7778, that added together give a palindrome (12921).

The spelling of 51437778 in words is "fifty-one million, four hundred thirty-seven thousand, seven hundred seventy-eight".