20397580999 has 4 divisors (see below), whose sum is σ = 20397869064. Its totient is φ = 20397292936.

The previous prime is 20397580963. The next prime is 20397581047. The reversal of 20397580999 is 99908579302.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20397580999 - 2⁹ = 20397580487 is a prime.

It is a super-2 number, since 2×20397580999² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20397580919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44049 + ... + 206725.

It is an arithmetic number, because the mean of its divisors is an integer number (5099467266).

Almost surely, 2^20397580999 is an apocalyptic number.

20397580999 is a deficient number, since it is larger than the sum of its proper divisors (288065).

20397580999 is a wasteful number, since it uses less digits than its factorization.

20397580999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288064.

The product of its (nonzero) digits is 11022480, while the sum is 61.

The spelling of 20397580999 in words is "twenty billion, three hundred ninety-seven million, five hundred eighty thousand, nine hundred ninety-nine".