640801560 has 128 divisors (see below), whose sum is σ = 2202163200. Its totient is φ = 146127360.

The previous prime is 640801559. The next prime is 640801561. The reversal of 640801560 is 65108046.

It is an interprime number because it is at equal distance from previous prime (640801559) and next prime (640801561).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640801561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 603430 + ... + 604490.

It is an arithmetic number, because the mean of its divisors is an integer number (17204400).

Almost surely, 2^640801560 is an apocalyptic number.

640801560 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 640801560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1101081600).

640801560 is an abundant number, since it is smaller than the sum of its proper divisors (1561361640).

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

640801560 is a wasteful number, since it uses less digits than its factorization.

640801560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1801 (or 1797 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 640801560 is about 25314.0585446111. The cubic root of 640801560 is about 862.1334985592.

The spelling of 640801560 in words is "six hundred forty million, eight hundred one thousand, five hundred sixty".