1639985139 has 24 divisors (see below), whose sum is σ = 2557995440. Its totient is φ = 1006489152.

The previous prime is 1639985107. The next prime is 1639985141. The reversal of 1639985139 is 9315899361.

1639985139 is a `hidden beast` number, since 1 + 6 + 39 + 98 + 513 + 9 = 666.

It is not a de Polignac number, because 1639985139 - 2⁵ = 1639985107 is a prime.

It is a super-2 number, since 2×1639985139² = 5379102512281698642, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1639985639) 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, 24852 + ... + 62430.

Almost surely, 2^1639985139 is an apocalyptic number.

1639985139 is a deficient number, since it is larger than the sum of its proper divisors (918010301).

1639985139 is a wasteful number, since it uses less digits than its factorization.

1639985139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37971 (or 37968 counting only the distinct ones).

The product of its digits is 1574640, while the sum is 54.

The square root of 1639985139 is about 40496.7299790983. The cubic root of 1639985139 is about 1179.2701459535.

The spelling of 1639985139 in words is "one billion, six hundred thirty-nine million, nine hundred eighty-five thousand, one hundred thirty-nine".