640190880 has 432 divisors, whose sum is σ = 2612754144. Its totient is φ = 142248960.

The previous prime is 640190861. The next prime is 640190891. The reversal of 640190880 is 88091046.

It is a happy number.

640190880 is a `hidden beast` number, since 640 + 1 + 9 + 0 + 8 + 8 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3033975 + ... + 3034185.

It is an arithmetic number, because the mean of its divisors is an integer number (6048042).

Almost surely, 2^640190880 is an apocalyptic number.

640190880 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 640190880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1306377072).

640190880 is an abundant number, since it is smaller than the sum of its proper divisors (1972563264).

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

640190880 is a wasteful number, since it uses less digits than its factorization.

640190880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 640190880 is about 25301.9935973433. The cubic root of 640190880 is about 861.8595421828.

The spelling of 640190880 in words is "six hundred forty million, one hundred ninety thousand, eight hundred eighty".