51685685480 has 256 divisors, whose sum is σ = 145170144000. Its totient is φ = 16271032320.

The previous prime is 51685685479. The next prime is 51685685567. The reversal of 51685685480 is 8458658615.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 33935999 + ... + 33937521.

It is an arithmetic number, because the mean of its divisors is an integer number (567070875).

Almost surely, 2^51685685480 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 51685685480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72585072000).

51685685480 is an abundant number, since it is smaller than the sum of its proper divisors (93484458520).

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

51685685480 is a wasteful number, since it uses less digits than its factorization.

51685685480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1924 (or 1920 counting only the distinct ones).

The product of its (nonzero) digits is 9216000, while the sum is 56.

The spelling of 51685685480 in words is "fifty-one billion, six hundred eighty-five million, six hundred eighty-five thousand, four hundred eighty".