21264207 has 4 divisors (see below), whose sum is σ = 28352280. Its totient is φ = 14176136.

The previous prime is 21264203. The next prime is 21264209. The reversal of 21264207 is 70246212.

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

It is a cyclic number.

It is not a de Polignac number, because 21264207 - 2² = 21264203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264203) 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, 3544032 + ... + 3544037.

It is an arithmetic number, because the mean of its divisors is an integer number (7088070).

Almost surely, 2^21264207 is an apocalyptic number.

21264207 is a deficient number, since it is larger than the sum of its proper divisors (7088073).

21264207 is an equidigital number, since it uses as much as digits as its factorization.

21264207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7088072.

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

The square root of 21264207 is about 4611.3129366808. The cubic root of 21264207 is about 277.0446260866.

The spelling of 21264207 in words is "twenty-one million, two hundred sixty-four thousand, two hundred seven".