21989349 has 12 divisors (see below), whose sum is σ = 31809856. Its totient is φ = 14637672.

The previous prime is 21989291. The next prime is 21989369. The reversal of 21989349 is 94398912.

It is not a de Polignac number, because 21989349 - 2¹² = 21985253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21989369) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6564 + ... + 9330.

Almost surely, 2^21989349 is an apocalyptic number.

It is an amenable number.

21989349 is a deficient number, since it is larger than the sum of its proper divisors (9820507).

21989349 is a wasteful number, since it uses less digits than its factorization.

21989349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3656 (or 3653 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 21989349 is about 4689.2802219530. The cubic root of 21989349 is about 280.1587067951.

The spelling of 21989349 in words is "twenty-one million, nine hundred eighty-nine thousand, three hundred forty-nine".