51432778656 has 960 divisors, whose sum is σ = 193636396800. Its totient is φ = 13330759680.

The previous prime is 51432778601. The next prime is 51432778679. The reversal of 51432778656 is 65687723415.

51432778656 is a `hidden beast` number, since 514 + 3 + 2 + 7 + 78 + 6 + 56 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 619671991 + ... + 619672073.

It is an arithmetic number, because the mean of its divisors is an integer number (201704580).

Almost surely, 2^51432778656 is an apocalyptic number.

51432778656 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51432778656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96818198400).

51432778656 is an abundant number, since it is smaller than the sum of its proper divisors (142203618144).

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

51432778656 is a wasteful number, since it uses less digits than its factorization.

51432778656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 153 counting only the distinct ones).

The product of its digits is 8467200, while the sum is 54.

The spelling of 51432778656 in words is "fifty-one billion, four hundred thirty-two million, seven hundred seventy-eight thousand, six hundred fifty-six".