21992397909 has 8 divisors (see below), whose sum is σ = 30038397312. Its totient is φ = 14303998560.

The previous prime is 21992397907. The next prime is 21992397919. The reversal of 21992397909 is 90979329912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21992397909 - 2¹ = 21992397907 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21992397901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89399869 + ... + 89400114.

It is an arithmetic number, because the mean of its divisors is an integer number (3754799664).

Almost surely, 2^21992397909 is an apocalyptic number.

It is an amenable number.

21992397909 is a deficient number, since it is larger than the sum of its proper divisors (8045999403).

21992397909 is a wasteful number, since it uses less digits than its factorization.

21992397909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178800027.

The product of its (nonzero) digits is 4960116, while the sum is 60.

The spelling of 21992397909 in words is "twenty-one billion, nine hundred ninety-two million, three hundred ninety-seven thousand, nine hundred nine".