640589796 has 216 divisors, whose sum is σ = 2102982336. Its totient is φ = 165862080.

The previous prime is 640589783. The next prime is 640589821. The reversal of 640589796 is 697985046.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 71 ways as a sum of consecutive naturals, for example, 2020630 + ... + 2020946.

Almost surely, 2^640589796 is an apocalyptic number.

640589796 is a gapful number since it is divisible by the number (66) 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 640589796, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1051491168).

640589796 is an abundant number, since it is smaller than the sum of its proper divisors (1462392540).

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

640589796 is a wasteful number, since it uses less digits than its factorization.

640589796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363 (or 340 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The square root of 640589796 is about 25309.8754639370. The cubic root of 640589796 is about 862.0385191021.

The spelling of 640589796 in words is "six hundred forty million, five hundred eighty-nine thousand, seven hundred ninety-six".