640142885 has 4 divisors (see below), whose sum is σ = 768171468. Its totient is φ = 512114304.

The previous prime is 640142863. The next prime is 640142917. The reversal of 640142885 is 588241046.

It is a happy number.

640142885 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 270503809 + 369639076 = 16447^2 + 19226^2 .

It is a cyclic number.

It is not a de Polignac number, because 640142885 - 2⁶ = 640142821 is a prime.

It is a super-2 number, since 2×640142885² = 819565826432246450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64014284 + ... + 64014293.

It is an arithmetic number, because the mean of its divisors is an integer number (192042867).

Almost surely, 2^640142885 is an apocalyptic number.

It is an amenable number.

640142885 is a deficient number, since it is larger than the sum of its proper divisors (128028583).

640142885 is a wasteful number, since it uses less digits than its factorization.

640142885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128028582.

The product of its (nonzero) digits is 61440, while the sum is 38.

The square root of 640142885 is about 25301.0451365156. The cubic root of 640142885 is about 861.8380038241.

The spelling of 640142885 in words is "six hundred forty million, one hundred forty-two thousand, eight hundred eighty-five".