21246207 has 4 divisors (see below), whose sum is σ = 28328280. Its totient is φ = 14164136.

The previous prime is 21246193. The next prime is 21246221. The reversal of 21246207 is 70264212.

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

It is an interprime number because it is at equal distance from previous prime (21246193) and next prime (21246221).

It is a cyclic number.

It is not a de Polignac number, because 21246207 - 2⁶ = 21246143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21246287) 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, 3541032 + ... + 3541037.

It is an arithmetic number, because the mean of its divisors is an integer number (7082070).

Almost surely, 2^21246207 is an apocalyptic number.

21246207 is a deficient number, since it is larger than the sum of its proper divisors (7082073).

21246207 is an equidigital number, since it uses as much as digits as its factorization.

21246207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7082072.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 21246207 is about 4609.3608016730. The cubic root of 21246207 is about 276.9664319169.

The spelling of 21246207 in words is "twenty-one million, two hundred forty-six thousand, two hundred seven".