51297931520 has 144 divisors (see below), whose sum is σ = 134220748032. Its totient is φ = 18629345280.

The previous prime is 51297931457. The next prime is 51297931577. The reversal of 51297931520 is 2513979215.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (44).

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, 13416329 + ... + 13420151.

It is an arithmetic number, because the mean of its divisors is an integer number (932088528).

Almost surely, 2^51297931520 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 51297931520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67110374016).

51297931520 is an abundant number, since it is smaller than the sum of its proper divisors (82922816512).

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

51297931520 is a wasteful number, since it uses less digits than its factorization.

51297931520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4808 (or 4794 counting only the distinct ones).

The product of its (nonzero) digits is 170100, while the sum is 44.

The spelling of 51297931520 in words is "fifty-one billion, two hundred ninety-seven million, nine hundred thirty-one thousand, five hundred twenty".