51544764540 has 144 divisors (see below), whose sum is σ = 164043000576. Its totient is φ = 13083724800.

The previous prime is 51544764463. The next prime is 51544764599. The reversal of 51544764540 is 4546744515.

51544764540 is a `hidden beast` number, since 5 + 1 + 5 + 4 + 47 + 64 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 264664 + ... + 416096.

It is an arithmetic number, because the mean of its divisors is an integer number (1139187504).

Almost surely, 2^51544764540 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 51544764540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82021500288).

51544764540 is an abundant number, since it is smaller than the sum of its proper divisors (112498236036).

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

51544764540 is a wasteful number, since it uses less digits than its factorization.

51544764540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151540 (or 151535 counting only the distinct ones).

The product of its (nonzero) digits is 1344000, while the sum is 45.

The spelling of 51544764540 in words is "fifty-one billion, five hundred forty-four million, seven hundred sixty-four thousand, five hundred forty".