51556550661 has 48 divisors (see below), whose sum is σ = 93438004608. Its totient is φ = 26611977600.

The previous prime is 51556550659. The next prime is 51556550713. The reversal of 51556550661 is 16605565515.

It is not a de Polignac number, because 51556550661 - 2¹ = 51556550659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51556550651) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 128130 + ... + 345731.

It is an arithmetic number, because the mean of its divisors is an integer number (1946625096).

Almost surely, 2^51556550661 is an apocalyptic number.

It is an amenable number.

51556550661 is a deficient number, since it is larger than the sum of its proper divisors (41881453947).

51556550661 is a wasteful number, since it uses less digits than its factorization.

51556550661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474042 (or 474039 counting only the distinct ones).

The product of its (nonzero) digits is 675000, while the sum is 45.

The spelling of 51556550661 in words is "fifty-one billion, five hundred fifty-six million, five hundred fifty thousand, six hundred sixty-one".