21393781339 has 8 divisors (see below), whose sum is σ = 24970249728. Its totient is φ = 17947366440.

The previous prime is 21393781333. The next prime is 21393781399. The reversal of 21393781339 is 93318739312.

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

It is a cyclic number.

It is not a de Polignac number, because 21393781339 - 2²¹ = 21391684187 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21393781292 and 21393781301.

It is not an unprimeable number, because it can be changed into a prime (21393781333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32513017 + ... + 32513674.

It is an arithmetic number, because the mean of its divisors is an integer number (3121281216).

Almost surely, 2^21393781339 is an apocalyptic number.

21393781339 is a deficient number, since it is larger than the sum of its proper divisors (3576468389).

21393781339 is an equidigital number, since it uses as much as digits as its factorization.

21393781339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65026745.

The product of its digits is 734832, while the sum is 49.

The spelling of 21393781339 in words is "twenty-one billion, three hundred ninety-three million, seven hundred eighty-one thousand, three hundred thirty-nine".