651842640 has 140 divisors (see below), whose sum is σ = 2272465044. Its totient is φ = 173809152.

The previous prime is 651842617. The next prime is 651842651. The reversal of 651842640 is 46248156.

651842640 is a `hidden beast` number, since 6 + 5 + 1 + 8 + 4 + 2 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 416649744 + 235192896 = 20412^2 + 15336^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 651842595 and 651842604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 52732 + ... + 63908.

Almost surely, 2^651842640 is an apocalyptic number.

651842640 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 651842640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1136232522).

651842640 is an abundant number, since it is smaller than the sum of its proper divisors (1620622404).

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

651842640 is a wasteful number, since it uses less digits than its factorization.

651842640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11208 (or 11187 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 651842640 is about 25531.2091370542. The cubic root of 651842640 is about 867.0568801657.

The spelling of 651842640 in words is "six hundred fifty-one million, eight hundred forty-two thousand, six hundred forty".