51551661000 has 128 divisors (see below), whose sum is σ = 183818568960. Its totient is φ = 11783232000.

The previous prime is 51551660983. The next prime is 51551661011. The reversal of 51551661000 is 16615515.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1206421 + ... + 1248420.

It is an arithmetic number, because the mean of its divisors is an integer number (1436082570).

Almost surely, 2^51551661000 is an apocalyptic number.

51551661000 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51551661000 is an abundant number, since it is smaller than the sum of its proper divisors (132266907960).

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

51551661000 is a wasteful number, since it uses less digits than its factorization.

51551661000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2454872 (or 2454858 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 30.

The spelling of 51551661000 in words is "fifty-one billion, five hundred fifty-one million, six hundred sixty-one thousand".