51299619840 has 880 divisors, whose sum is σ = 215713580544. Its totient is φ = 11413094400.

The previous prime is 51299619823. The next prime is 51299619841. The reversal of 51299619840 is 4891699215.

51299619840 is a `hidden beast` number, since 5 + 12 + 9 + 9 + 619 + 8 + 4 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51299619841) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 119024425 + ... + 119024855.

Almost surely, 2^51299619840 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 51299619840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107856790272).

51299619840 is an abundant number, since it is smaller than the sum of its proper divisors (164413960704).

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

51299619840 is a wasteful number, since it uses less digits than its factorization.

51299619840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The spelling of 51299619840 in words is "fifty-one billion, two hundred ninety-nine million, six hundred nineteen thousand, eight hundred forty".