21392138699 has 4 divisors (see below), whose sum is σ = 21560580864. Its totient is φ = 21223696536.

The previous prime is 21392138657. The next prime is 21392138723. The reversal of 21392138699 is 99683129312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21392138699 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 21392138699.

It is not an unprimeable number, because it can be changed into a prime (21392138629) 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 3 ways as a sum of consecutive naturals, for example, 84220892 + ... + 84221145.

It is an arithmetic number, because the mean of its divisors is an integer number (5390145216).

Almost surely, 2^21392138699 is an apocalyptic number.

21392138699 is a deficient number, since it is larger than the sum of its proper divisors (168442165).

21392138699 is a wasteful number, since it uses less digits than its factorization.

21392138699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168442164.

The product of its digits is 1259712, while the sum is 53.

The spelling of 21392138699 in words is "twenty-one billion, three hundred ninety-two million, one hundred thirty-eight thousand, six hundred ninety-nine".