51555666456 has 64 divisors (see below), whose sum is σ = 163668787200. Its totient is φ = 14730189984.

The previous prime is 51555666433. The next prime is 51555666479. The reversal of 51555666456 is 65466655515.

It is an interprime number because it is at equal distance from previous prime (51555666433) and next prime (51555666479).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17047320 + ... + 17050343.

It is an arithmetic number, because the mean of its divisors is an integer number (2557324800).

Almost surely, 2^51555666456 is an apocalyptic number.

51555666456 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

51555666456 is an abundant number, since it is smaller than the sum of its proper divisors (112113120744).

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

51555666456 is a wasteful number, since it uses less digits than its factorization.

51555666456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34097685 (or 34097675 counting only the distinct ones).

The product of its digits is 16200000, while the sum is 54.

The spelling of 51555666456 in words is "fifty-one billion, five hundred fifty-five million, six hundred sixty-six thousand, four hundred fifty-six".