51388880 has 20 divisors (see below), whose sum is σ = 119479332. Its totient is φ = 20555520.

The previous prime is 51388879. The next prime is 51388889. The reversal of 51388880 is 8888315.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 30558784 + 20830096 = 5528^2 + 4564^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51388889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 321101 + ... + 321260.

Almost surely, 2^51388880 is an apocalyptic number.

It is an amenable number.

51388880 is an abundant number, since it is smaller than the sum of its proper divisors (68090452).

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

51388880 is a wasteful number, since it uses less digits than its factorization.

51388880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642374 (or 642368 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 41.

The square root of 51388880 is about 7168.6037692148. The cubic root of 51388880 is about 371.7831626431.

The spelling of 51388880 in words is "fifty-one million, three hundred eighty-eight thousand, eight hundred eighty".