51805401664 has 63 divisors (see below), whose sum is σ = 107552245017. Its totient is φ = 24756466944.

The previous prime is 51805401649. The next prime is 51805401671. The reversal of 51805401664 is 46610450815.

The square root of 51805401664 is 227608.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 39124840000 + 12680561664 = 197800^2 + 112608^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 41879254 + ... + 41880490.

Almost surely, 2^51805401664 is an apocalyptic number.

51805401664 is the 227608-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51805401664

51805401664 is an abundant number, since it is smaller than the sum of its proper divisors (55746843353).

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

51805401664 is an frugal number, since it uses more digits than its factorization.

51805401664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2532 (or 1262 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 40.

The spelling of 51805401664 in words is "fifty-one billion, eight hundred five million, four hundred one thousand, six hundred sixty-four".