639959862 has 48 divisors (see below), whose sum is σ = 1356238080. Its totient is φ = 201284784.

The previous prime is 639959839. The next prime is 639959863. The reversal of 639959862 is 268959936.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639959863) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 777183 + ... + 778005.

It is an arithmetic number, because the mean of its divisors is an integer number (28254960).

Almost surely, 2^639959862 is an apocalyptic number.

639959862 is an abundant number, since it is smaller than the sum of its proper divisors (716278218).

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

639959862 is a wasteful number, since it uses less digits than its factorization.

639959862 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1225 (or 1206 counting only the distinct ones).

The product of its digits is 6298560, while the sum is 57.

The square root of 639959862 is about 25297.4279720291. The cubic root of 639959862 is about 861.7558600737.

The spelling of 639959862 in words is "six hundred thirty-nine million, nine hundred fifty-nine thousand, eight hundred sixty-two".