51504455440 has 20 divisors (see below), whose sum is σ = 119747859084. Its totient is φ = 20601782144.

The previous prime is 51504455383. The next prime is 51504455461. The reversal of 51504455440 is 4455440515.

It can be written as a sum of positive squares in 2 ways, for example, as 23505795856 + 27998659584 = 153316^2 + 167328^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 51504455440.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 321902767 + ... + 321902926.

Almost surely, 2^51504455440 is an apocalyptic number.

It is an amenable number.

51504455440 is an abundant number, since it is smaller than the sum of its proper divisors (68243403644).

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

51504455440 is a wasteful number, since it uses less digits than its factorization.

51504455440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643805706 (or 643805700 counting only the distinct ones).

The product of its (nonzero) digits is 160000, while the sum is 37.

Adding to 51504455440 its reverse (4455440515), we get a palindrome (55959895955).

It can be divided in two parts, 51504 and 455440, that added together give a square (506944 = 712²).

The spelling of 51504455440 in words is "fifty-one billion, five hundred four million, four hundred fifty-five thousand, four hundred forty".