651343680 has 280 divisors, whose sum is σ = 2496461352. Its totient is φ = 160247808.

The previous prime is 651343643. The next prime is 651343681. The reversal of 651343680 is 86343156.

It can be written as a sum of positive squares in 4 ways, for example, as 30735936 + 620607744 = 5544^2 + 24912^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651343681) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 335994 + ... + 337926.

Almost surely, 2^651343680 is an apocalyptic number.

651343680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 651343680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1248230676).

651343680 is an abundant number, since it is smaller than the sum of its proper divisors (1845117672).

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

651343680 is a wasteful number, since it uses less digits than its factorization.

651343680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1975 (or 1956 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 651343680 is about 25521.4356962926. The cubic root of 651343680 is about 866.8355910040.

The spelling of 651343680 in words is "six hundred fifty-one million, three hundred forty-three thousand, six hundred eighty".