21796989 has 4 divisors (see below), whose sum is σ = 29062656. Its totient is φ = 14531324.

The previous prime is 21796981. The next prime is 21797003. The reversal of 21796989 is 98969712.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21796989 - 2³ = 21796981 is a prime.

It is a super-2 number, since 2×21796989² = 950217458932242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21796981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3632829 + ... + 3632834.

It is an arithmetic number, because the mean of its divisors is an integer number (7265664).

Almost surely, 2^21796989 is an apocalyptic number.

It is an amenable number.

21796989 is a deficient number, since it is larger than the sum of its proper divisors (7265667).

21796989 is an equidigital number, since it uses as much as digits as its factorization.

21796989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7265666.

The product of its digits is 489888, while the sum is 51.

The square root of 21796989 is about 4668.7245581636. The cubic root of 21796989 is about 279.3393822236.

The spelling of 21796989 in words is "twenty-one million, seven hundred ninety-six thousand, nine hundred eighty-nine".