21311221394 has 8 divisors (see below), whose sum is σ = 31984489008. Its totient is φ = 10649725060.

The previous prime is 21311221381. The next prime is 21311221397. The reversal of 21311221394 is 49312211312.

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

It is not an unprimeable number, because it can be changed into a prime (21311221397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2938292 + ... + 2945535.

It is an arithmetic number, because the mean of its divisors is an integer number (3998061126).

Almost surely, 2^21311221394 is an apocalyptic number.

21311221394 is a deficient number, since it is larger than the sum of its proper divisors (10673267614).

21311221394 is a wasteful number, since it uses less digits than its factorization.

21311221394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5885640.

The product of its digits is 2592, while the sum is 29.

The spelling of 21311221394 in words is "twenty-one billion, three hundred eleven million, two hundred twenty-one thousand, three hundred ninety-four".