20879215509 has 16 divisors (see below), whose sum is σ = 28027828224. Its totient is φ = 13825344000.

The previous prime is 20879215457. The next prime is 20879215543. The reversal of 20879215509 is 90551297802.

It is not a de Polignac number, because 20879215509 - 2¹⁷ = 20879084437 is a prime.

It is a super-3 number, since 3×20879215509³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20879215559) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 239209 + ... + 314609.

It is an arithmetic number, because the mean of its divisors is an integer number (1751739264).

Almost surely, 2^20879215509 is an apocalyptic number.

It is an amenable number.

20879215509 is a deficient number, since it is larger than the sum of its proper divisors (7148612715).

20879215509 is a wasteful number, since it uses less digits than its factorization.

20879215509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76028.

The product of its (nonzero) digits is 453600, while the sum is 48.

The spelling of 20879215509 in words is "twenty billion, eight hundred seventy-nine million, two hundred fifteen thousand, five hundred nine".