640769376 has 192 divisors, whose sum is σ = 1942375680. Its totient is φ = 183306240.

The previous prime is 640769369. The next prime is 640769383. The reversal of 640769376 is 673967046.

It is an interprime number because it is at equal distance from previous prime (640769369) and next prime (640769383).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1446211 + ... + 1446653.

It is an arithmetic number, because the mean of its divisors is an integer number (10116540).

Almost surely, 2^640769376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640769376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (971187840).

640769376 is an abundant number, since it is smaller than the sum of its proper divisors (1301606304).

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

640769376 is a wasteful number, since it uses less digits than its factorization.

640769376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549 (or 541 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 48.

The square root of 640769376 is about 25313.4228424368. The cubic root of 640769376 is about 862.1190648818.

The spelling of 640769376 in words is "six hundred forty million, seven hundred sixty-nine thousand, three hundred seventy-six".