651815680 has 72 divisors (see below), whose sum is σ = 1603616112. Its totient is φ = 253661184.

The previous prime is 651815651. The next prime is 651815701. The reversal of 651815680 is 86518156.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40479 + ... + 54241.

It is an arithmetic number, because the mean of its divisors is an integer number (22272446).

Almost surely, 2^651815680 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 651815680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (801808056).

651815680 is an abundant number, since it is smaller than the sum of its proper divisors (951800432).

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

651815680 is a wasteful number, since it uses less digits than its factorization.

651815680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13821 (or 13807 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 40.

The square root of 651815680 is about 25530.6811503336. The cubic root of 651815680 is about 867.0449262705.

The spelling of 651815680 in words is "six hundred fifty-one million, eight hundred fifteen thousand, six hundred eighty".