20397607009639 has 4 divisors (see below), whose sum is σ = 20399049264256. Its totient is φ = 20396164755024.

The previous prime is 20397607009589. The next prime is 20397607009649. The reversal of 20397607009639 is 93690070679302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20397607009639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20397607009649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 721106094 + ... + 721134379.

It is an arithmetic number, because the mean of its divisors is an integer number (5099762316064).

Almost surely, 2^{20397607009639} is an apocalyptic number.

20397607009639 is a deficient number, since it is larger than the sum of its proper divisors (1442254617).

20397607009639 is a wasteful number, since it uses less digits than its factorization.

20397607009639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442254616.

The product of its (nonzero) digits is 23147208, while the sum is 61.

The spelling of 20397607009639 in words is "twenty trillion, three hundred ninety-seven billion, six hundred seven million, nine thousand, six hundred thirty-nine".