51551172 has 18 divisors (see below), whose sum is σ = 130309998. Its totient is φ = 17183712.

The previous prime is 51551147. The next prime is 51551173. The reversal of 51551172 is 27115515.

It can be written as a sum of positive squares in only one way, i.e., 33454656 + 18096516 = 5784^2 + 4254^2 .

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

It is not an unprimeable number, because it can be changed into a prime (51551173) 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, 715953 + ... + 716024.

Almost surely, 2^51551172 is an apocalyptic number.

It is an amenable number.

51551172 is an abundant number, since it is smaller than the sum of its proper divisors (78758826).

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

51551172 is a wasteful number, since it uses less digits than its factorization.

51551172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1431987 (or 1431982 counting only the distinct ones).

The product of its digits is 1750, while the sum is 27.

The square root of 51551172 is about 7179.9144841704. The cubic root of 51551172 is about 372.1741293705.

Adding to 51551172 its reverse (27115515), we get a palindrome (78666687).

The spelling of 51551172 in words is "fifty-one million, five hundred fifty-one thousand, one hundred seventy-two".