21068997 has 4 divisors (see below), whose sum is σ = 28092000. Its totient is φ = 14045996.

The previous prime is 21068977. The next prime is 21069007. The reversal of 21068997 is 79986012.

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 21068997 - 2⁷ = 21068869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21068977) 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, 3511497 + ... + 3511502.

It is an arithmetic number, because the mean of its divisors is an integer number (7023000).

Almost surely, 2^21068997 is an apocalyptic number.

It is an amenable number.

21068997 is a deficient number, since it is larger than the sum of its proper divisors (7023003).

21068997 is an equidigital number, since it uses as much as digits as its factorization.

21068997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7023002.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 21068997 is about 4590.0977113783. The cubic root of 21068997 is about 276.1942420721.

The spelling of 21068997 in words is "twenty-one million, sixty-eight thousand, nine hundred ninety-seven".