639139470 has 32 divisors (see below), whose sum is σ = 1534677408. Its totient is φ = 170354688.

The previous prime is 639139453. The next prime is 639139477. The reversal of 639139470 is 74931936.

639139470 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×639139470² = 816998524223761800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639139477) 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, 81982 + ... + 89438.

It is an arithmetic number, because the mean of its divisors is an integer number (47958669).

Almost surely, 2^639139470 is an apocalyptic number.

639139470 is an abundant number, since it is smaller than the sum of its proper divisors (895537938).

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

639139470 is a wasteful number, since it uses less digits than its factorization.

639139470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10324.

The product of its (nonzero) digits is 122472, while the sum is 42.

The square root of 639139470 is about 25281.2078429809. The cubic root of 639139470 is about 861.3874620056.

The spelling of 639139470 in words is "six hundred thirty-nine million, one hundred thirty-nine thousand, four hundred seventy".