1639385797 has 24 divisors (see below), whose sum is σ = 2040390240. Its totient is φ = 1309361760.

The previous prime is 1639385777. The next prime is 1639385809. The reversal of 1639385797 is 7975839361.

It is a happy number.

It is not a de Polignac number, because 1639385797 - 2¹⁵ = 1639353029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1639385717) 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, 42358 + ... + 71224.

It is an arithmetic number, because the mean of its divisors is an integer number (85016260).

Almost surely, 2^1639385797 is an apocalyptic number.

It is an amenable number.

1639385797 is a deficient number, since it is larger than the sum of its proper divisors (401004443).

1639385797 is a wasteful number, since it uses less digits than its factorization.

1639385797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28961 (or 28954 counting only the distinct ones).

The product of its digits is 8573040, while the sum is 58.

The square root of 1639385797 is about 40489.3294214661. The cubic root of 1639385797 is about 1179.1264714311.

The spelling of 1639385797 in words is "one billion, six hundred thirty-nine million, three hundred eighty-five thousand, seven hundred ninety-seven".