20871979019 has 16 divisors (see below), whose sum is σ = 21620464320. Its totient is φ = 20135485440.

The previous prime is 20871978991. The next prime is 20871979021. The reversal of 20871979019 is 91097917802.

It is a cyclic number.

It is not a de Polignac number, because 20871979019 - 2²⁴ = 20855201803 is a prime.

It is a super-2 number, since 2×20871979019² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20871979519) 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, 3193547 + ... + 3200075.

It is an arithmetic number, because the mean of its divisors is an integer number (1351279020).

Almost surely, 2^20871979019 is an apocalyptic number.

20871979019 is a deficient number, since it is larger than the sum of its proper divisors (748485301).

20871979019 is a wasteful number, since it uses less digits than its factorization.

20871979019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7430.

The product of its (nonzero) digits is 571536, while the sum is 53.

The spelling of 20871979019 in words is "twenty billion, eight hundred seventy-one million, nine hundred seventy-nine thousand, nineteen".