51204640521663 has 20 divisors (see below), whose sum is σ = 78958330589248. Its totient is φ = 33035251947840.

The previous prime is 51204640521611. The next prime is 51204640521689. The reversal of 51204640521663 is 36612504640215.

51204640521663 is a `hidden beast` number, since 5 + 1 + 2 + 0 + 4 + 64 + 0 + 521 + 6 + 63 = 666.

It is not a de Polignac number, because 51204640521663 - 2⁸ = 51204640521407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51204640021663) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10196062906 + ... + 10196067927.

Almost surely, 2^{51204640521663} is an apocalyptic number.

51204640521663 is a deficient number, since it is larger than the sum of its proper divisors (27753690067585).

51204640521663 is a wasteful number, since it uses less digits than its factorization.

51204640521663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20392130876 (or 20392130867 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 45.

The spelling of 51204640521663 in words is "fifty-one trillion, two hundred four billion, six hundred forty million, five hundred twenty-one thousand, six hundred sixty-three".