20879609509 has 8 divisors (see below), whose sum is σ = 22807696320. Its totient is φ = 18956512800.

The previous prime is 20879609501. The next prime is 20879609519. The reversal of 20879609509 is 90590697802.

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 20879609509 - 2³ = 20879609501 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20879609509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20879609501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1238769 + ... + 1255510.

It is an arithmetic number, because the mean of its divisors is an integer number (2850962040).

Almost surely, 2^20879609509 is an apocalyptic number.

It is an amenable number.

20879609509 is a deficient number, since it is larger than the sum of its proper divisors (1928086811).

20879609509 is a wasteful number, since it uses less digits than its factorization.

20879609509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2495051.

The product of its (nonzero) digits is 2449440, while the sum is 55.

The spelling of 20879609509 in words is "twenty billion, eight hundred seventy-nine million, six hundred nine thousand, five hundred nine".