51665611550 has 48 divisors (see below), whose sum is σ = 112380461952. Its totient is φ = 17301967200.

The previous prime is 51665611541. The next prime is 51665611567. The reversal of 51665611550 is 5511656615.

It is a junction number, because it is equal to n+sod(n) for n = 51665611498 and 51665611507.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1701416 + ... + 1731515.

It is an arithmetic number, because the mean of its divisors is an integer number (2341259624).

Almost surely, 2^51665611550 is an apocalyptic number.

51665611550 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

51665611550 is an abundant number, since it is smaller than the sum of its proper divisors (60714850402).

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

51665611550 is a wasteful number, since it uses less digits than its factorization.

51665611550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3432993 (or 3432988 counting only the distinct ones).

The product of its (nonzero) digits is 135000, while the sum is 41.

The spelling of 51665611550 in words is "fifty-one billion, six hundred sixty-five million, six hundred eleven thousand, five hundred fifty".