646738139 has 8 divisors (see below), whose sum is σ = 650525040. Its totient is φ = 642962016.

The previous prime is 646738129. The next prime is 646738177. The reversal of 646738139 is 931837646.

It is a happy number.

646738139 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646738139 - 2¹⁶ = 646672603 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646738093 and 646738102.

It is not an unprimeable number, because it can be changed into a prime (646738109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138389 + ... + 142985.

It is an arithmetic number, because the mean of its divisors is an integer number (81315630).

Almost surely, 2^646738139 is an apocalyptic number.

646738139 is a deficient number, since it is larger than the sum of its proper divisors (3786901).

646738139 is a wasteful number, since it uses less digits than its factorization.

646738139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5389.

The product of its digits is 653184, while the sum is 47.

The square root of 646738139 is about 25431.0467539187. The cubic root of 646738139 is about 864.7876739487.

The spelling of 646738139 in words is "six hundred forty-six million, seven hundred thirty-eight thousand, one hundred thirty-nine".