21200997 has 8 divisors (see below), whose sum is σ = 28306656. Its totient is φ = 14114672.

The previous prime is 21200987. The next prime is 21201031. The reversal of 21200997 is 79900212.

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 21200997 - 2¹⁰ = 21199973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200987) 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, 2043 + ... + 6824.

It is an arithmetic number, because the mean of its divisors is an integer number (3538332).

Almost surely, 2^21200997 is an apocalyptic number.

It is an amenable number.

21200997 is a deficient number, since it is larger than the sum of its proper divisors (7105659).

21200997 is an equidigital number, since it uses as much as digits as its factorization.

21200997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9667.

The product of its (nonzero) digits is 2268, while the sum is 30.

The square root of 21200997 is about 4604.4540392972. The cubic root of 21200997 is about 276.7698392647.

The spelling of 21200997 in words is "twenty-one million, two hundred thousand, nine hundred ninety-seven".