51656605054551 has 80 divisors (see below), whose sum is σ = 89491599504384. Its totient is φ = 29084227436736.

The previous prime is 51656605054543. The next prime is 51656605054601. The reversal of 51656605054551 is 15545050665615.

It is not a de Polignac number, because 51656605054551 - 2³ = 51656605054543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51656605054751) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 16082370 + ... + 19025136.

Almost surely, 2^{51656605054551} is an apocalyptic number.

51656605054551 is a deficient number, since it is larger than the sum of its proper divisors (37834994449833).

51656605054551 is a wasteful number, since it uses less digits than its factorization.

51656605054551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2943242 (or 2943233 counting only the distinct ones).

The product of its (nonzero) digits is 13500000, while the sum is 54.

The spelling of 51656605054551 in words is "fifty-one trillion, six hundred fifty-six billion, six hundred five million, fifty-four thousand, five hundred fifty-one".