51405564 has 96 divisors (see below), whose sum is σ = 149094400. Its totient is φ = 13452480.

The previous prime is 51405539. The next prime is 51405577. The reversal of 51405564 is 46550415.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48957 + ... + 49995.

Almost surely, 2^51405564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51405564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74547200).

51405564 is an abundant number, since it is smaller than the sum of its proper divisors (97688836).

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

51405564 is a wasteful number, since it uses less digits than its factorization.

51405564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1103 (or 1101 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 51405564 is about 7169.7673602426. The cubic root of 51405564 is about 371.8233928715.

Adding to 51405564 its reverse (46550415), we get a palindrome (97955979).

The spelling of 51405564 in words is "fifty-one million, four hundred five thousand, five hundred sixty-four".