51657444 has 18 divisors (see below), whose sum is σ = 130578630. Its totient is φ = 17219136.

The previous prime is 51657443. The next prime is 51657451. The reversal of 51657444 is 44475615.

It can be written as a sum of positive squares in only one way, i.e., 47196900 + 4460544 = 6870^2 + 2112^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×51657444² = 5336983041226272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 1434929 = 51657444 / (5 + 1 + 6 + 5 + 7 + 4 + 4 + 4).

It is a junction number, because it is equal to n+sod(n) for n = 51657399 and 51657408.

It is not an unprimeable number, because it can be changed into a prime (51657443) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 717429 + ... + 717500.

Almost surely, 2^51657444 is an apocalyptic number.

It is an amenable number.

51657444 is an abundant number, since it is smaller than the sum of its proper divisors (78921186).

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

51657444 is a wasteful number, since it uses less digits than its factorization.

51657444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434939 (or 1434934 counting only the distinct ones).

The product of its digits is 67200, while the sum is 36.

The square root of 51657444 is about 7187.3113192626. The cubic root of 51657444 is about 372.4296977066.

The spelling of 51657444 in words is "fifty-one million, six hundred fifty-seven thousand, four hundred forty-four".