51897615840 has 1536 divisors, whose sum is σ = 234101145600. Its totient is φ = 10474168320.

The previous prime is 51897615823. The next prime is 51897615853. The reversal of 51897615840 is 4851679815.

It is a happy number.

51897615840 is a `hidden beast` number, since 5 + 18 + 9 + 7 + 615 + 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 an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 625272439 + ... + 625272521.

It is an arithmetic number, because the mean of its divisors is an integer number (152409600).

Almost surely, 2^51897615840 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 51897615840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117050572800).

51897615840 is an abundant number, since it is smaller than the sum of its proper divisors (182203529760).

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

51897615840 is a wasteful number, since it uses less digits than its factorization.

51897615840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 54.

The spelling of 51897615840 in words is "fifty-one billion, eight hundred ninety-seven million, six hundred fifteen thousand, eight hundred forty".