6251408640 has 432 divisors, whose sum is σ = 23167701648. Its totient is φ = 1550843904.

The previous prime is 6251408617. The next prime is 6251408663. The reversal of 6251408640 is 468041526.

6251408640 is a `hidden beast` number, since 6 + 2 + 5 + 1 + 4 + 0 + 8 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (6251408617) and next prime (6251408663).

It can be written as a sum of positive squares in 8 ways, for example, as 9144576 + 6242264064 = 3024^2 + 79008^2 .

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 = 6251408595 and 6251408604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 26829964 + ... + 26830196.

It is an arithmetic number, because the mean of its divisors is an integer number (53628939).

Almost surely, 2^6251408640 is an apocalyptic number.

6251408640 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 6251408640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11583850824).

6251408640 is an abundant number, since it is smaller than the sum of its proper divisors (16916293008).

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

6251408640 is a wasteful number, since it uses less digits than its factorization.

6251408640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414 (or 397 counting only the distinct ones).

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

The square root of 6251408640 is about 79065.8500238883. The cubic root of 6251408640 is about 1842.1541249017.

The spelling of 6251408640 in words is "six billion, two hundred fifty-one million, four hundred eight thousand, six hundred forty".