6400740720 has 160 divisors (see below), whose sum is σ = 22919604480. Its totient is φ = 1460408320.

The previous prime is 6400740683. The next prime is 6400740733. The reversal of 6400740720 is 270470046.

It is a super-2 number, since 2×6400740720² = 81938963529332236800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26430 + ... + 116189.

It is an arithmetic number, because the mean of its divisors is an integer number (143247528).

Almost surely, 2^6400740720 is an apocalyptic number.

6400740720 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 6400740720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11459802240).

6400740720 is an abundant number, since it is smaller than the sum of its proper divisors (16518863760).

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

6400740720 is a wasteful number, since it uses less digits than its factorization.

6400740720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142663 (or 142657 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 30.

The square root of 6400740720 is about 80004.6293660561. The cubic root of 6400740720 is about 1856.7071581336.

The spelling of 6400740720 in words is "six billion, four hundred million, seven hundred forty thousand, seven hundred twenty".