21994890331 has 4 divisors (see below), whose sum is σ = 21996363672. Its totient is φ = 21993416992.

The previous prime is 21994890301. The next prime is 21994890403. The reversal of 21994890331 is 13309849912.

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

It is a cyclic number.

It is not a de Polignac number, because 21994890331 - 2¹¹ = 21994888283 is a prime.

It is a super-2 number, since 2×21994890331² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21994890301) 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, 714046 + ... + 744211.

It is an arithmetic number, because the mean of its divisors is an integer number (5499090918).

Almost surely, 2^21994890331 is an apocalyptic number.

21994890331 is a deficient number, since it is larger than the sum of its proper divisors (1473341).

21994890331 is a wasteful number, since it uses less digits than its factorization.

21994890331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1473340.

The product of its (nonzero) digits is 419904, while the sum is 49.

The spelling of 21994890331 in words is "twenty-one billion, nine hundred ninety-four million, eight hundred ninety thousand, three hundred thirty-one".