639142893 has 20 divisors (see below), whose sum is σ = 958966140. Its totient is φ = 424222272.

The previous prime is 639142877. The next prime is 639142961. The reversal of 639142893 is 398241936.

It is a happy number.

639142893 is a `hidden beast` number, since 639 + 1 + 4 + 2 + 8 + 9 + 3 = 666.

639142893 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 515199204 + 123943689 = 22698^2 + 11133^2 .

It is not a de Polignac number, because 639142893 - 2⁴ = 639142877 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639142873) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1321 + ... + 35777.

It is an arithmetic number, because the mean of its divisors is an integer number (47948307).

Almost surely, 2^639142893 is an apocalyptic number.

It is an amenable number.

639142893 is a deficient number, since it is larger than the sum of its proper divisors (319823247).

639142893 is a wasteful number, since it uses less digits than its factorization.

639142893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34698 (or 34689 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 639142893 is about 25281.2755413962. The cubic root of 639142893 is about 861.3889997628.

It can be divided in two parts, 6391 and 42893, that added together give a square (49284 = 222²).

The spelling of 639142893 in words is "six hundred thirty-nine million, one hundred forty-two thousand, eight hundred ninety-three".