21279858369 has 32 divisors (see below), whose sum is σ = 35381698560. Its totient is φ = 11052163200.

The previous prime is 21279858349. The next prime is 21279858373. The reversal of 21279858369 is 96385897212.

It is not a de Polignac number, because 21279858369 - 2⁵ = 21279858337 is a prime.

It is a super-2 number, since 2×21279858369² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21279858319) 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 31 ways as a sum of consecutive naturals, for example, 2066704 + ... + 2076974.

It is an arithmetic number, because the mean of its divisors is an integer number (1105678080).

Almost surely, 2^21279858369 is an apocalyptic number.

It is an amenable number.

21279858369 is a deficient number, since it is larger than the sum of its proper divisors (14101840191).

21279858369 is a wasteful number, since it uses less digits than its factorization.

21279858369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19261.

The product of its digits is 13063680, while the sum is 60.

The spelling of 21279858369 in words is "twenty-one billion, two hundred seventy-nine million, eight hundred fifty-eight thousand, three hundred sixty-nine".