640441377 has 16 divisors (see below), whose sum is σ = 949220160. Its totient is φ = 426772800.

The previous prime is 640441339. The next prime is 640441393. The reversal of 640441377 is 773144046.

It is a happy number.

640441377 is a `hidden beast` number, since 640 + 4 + 4 + 1 + 3 + 7 + 7 = 666.

It is not a de Polignac number, because 640441377 - 2¹¹ = 640439329 is a prime.

It is a super-2 number, since 2×640441377² = 820330314747312258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640441327) 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, 86377 + ... + 93497.

It is an arithmetic number, because the mean of its divisors is an integer number (59326260).

Almost surely, 2^640441377 is an apocalyptic number.

It is an amenable number.

640441377 is a deficient number, since it is larger than the sum of its proper divisors (308778783).

640441377 is a wasteful number, since it uses less digits than its factorization.

640441377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10461 (or 10455 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 36.

The square root of 640441377 is about 25306.9432567428. The cubic root of 640441377 is about 861.9719383884.

The spelling of 640441377 in words is "six hundred forty million, four hundred forty-one thousand, three hundred seventy-seven".