21936207 has 4 divisors (see below), whose sum is σ = 29248280. Its totient is φ = 14624136.

The previous prime is 21936191. The next prime is 21936217. The reversal of 21936207 is 70263912.

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

It is not a de Polignac number, because 21936207 - 2⁴ = 21936191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21936217) 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, 3656032 + ... + 3656037.

It is an arithmetic number, because the mean of its divisors is an integer number (7312070).

Almost surely, 2^21936207 is an apocalyptic number.

21936207 is a deficient number, since it is larger than the sum of its proper divisors (7312073).

21936207 is an equidigital number, since it uses as much as digits as its factorization.

21936207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7312072.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 21936207 is about 4683.6104662963. The cubic root of 21936207 is about 279.9328367821.

The spelling of 21936207 in words is "twenty-one million, nine hundred thirty-six thousand, two hundred seven".