640260780 has 48 divisors (see below), whose sum is σ = 1798621440. Its totient is φ = 170175168.

The previous prime is 640260779. The next prime is 640260781. The reversal of 640260780 is 87062046.

It is an interprime number because it is at equal distance from previous prime (640260779) and next prime (640260781).

It is not an unprimeable number, because it can be changed into a prime (640260781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1041 + ... + 35799.

It is an arithmetic number, because the mean of its divisors is an integer number (37471280).

Almost surely, 2^640260780 is an apocalyptic number.

640260780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640260780 is an abundant number, since it is smaller than the sum of its proper divisors (1158360660).

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

640260780 is a wasteful number, since it uses less digits than its factorization.

640260780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35078 (or 35076 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 640260780 is about 25303.3748737199. The cubic root of 640260780 is about 861.8909087598.

The spelling of 640260780 in words is "six hundred forty million, two hundred sixty thousand, seven hundred eighty".