640145277 has 12 divisors (see below), whose sum is σ = 925162524. Its totient is φ = 426528960.

The previous prime is 640145237. The next prime is 640145281. The reversal of 640145277 is 772541046.

640145277 is a `hidden beast` number, since 640 + 1 + 4 + 5 + 2 + 7 + 7 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 389904516 + 250240761 = 19746^2 + 15819^2 .

It is not a de Polignac number, because 640145277 - 2²⁷ = 505927549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640145237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1374 + ... + 35807.

It is an arithmetic number, because the mean of its divisors is an integer number (77096877).

Almost surely, 2^640145277 is an apocalyptic number.

It is an amenable number.

640145277 is a deficient number, since it is larger than the sum of its proper divisors (285017247).

640145277 is a wasteful number, since it uses less digits than its factorization.

640145277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39100 (or 39097 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 640145277 is about 25301.0924072460. The cubic root of 640145277 is about 861.8390772896.

The spelling of 640145277 in words is "six hundred forty million, one hundred forty-five thousand, two hundred seventy-seven".