51506605397520 has 640 divisors, whose sum is σ = 225396453703680. Its totient is φ = 10516767528960.

The previous prime is 51506605397477. The next prime is 51506605397521. The reversal of 51506605397520 is 2579350660515.

51506605397520 is a `hidden beast` number, since 5 + 1 + 5 + 0 + 6 + 60 + 53 + 9 + 7 + 520 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (51506605397521) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1866907 + ... + 10319813.

It is an arithmetic number, because the mean of its divisors is an integer number (352181958912).

Almost surely, 2^{51506605397520} 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 51506605397520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112698226851840).

51506605397520 is an abundant number, since it is smaller than the sum of its proper divisors (173889848306160).

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

51506605397520 is a wasteful number, since it uses less digits than its factorization.

51506605397520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8452980 (or 8452968 counting only the distinct ones).

The product of its (nonzero) digits is 8505000, while the sum is 54.

The spelling of 51506605397520 in words is "fifty-one trillion, five hundred six billion, six hundred five million, three hundred ninety-seven thousand, five hundred twenty".