51491066544432 has 360 divisors, whose sum is σ = 150536542075920. Its totient is φ = 16419238133760.

The previous prime is 51491066544403. The next prime is 51491066544443. The reversal of 51491066544432 is 23444566019415.

51491066544432 is a `hidden beast` number, since 5 + 1 + 4 + 9 + 1 + 0 + 66 + 544 + 4 + 32 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6309402432 + ... + 6309410592.

It is an arithmetic number, because the mean of its divisors is an integer number (418157061322).

Almost surely, 2^{51491066544432} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51491066544432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75268271037960).

51491066544432 is an abundant number, since it is smaller than the sum of its proper divisors (99045475531488).

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

51491066544432 is a wasteful number, since it uses less digits than its factorization.

51491066544432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8521 (or 8405 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 54.

The spelling of 51491066544432 in words is "fifty-one trillion, four hundred ninety-one billion, sixty-six million, five hundred forty-four thousand, four hundred thirty-two".