21875207 has 2 divisors, whose sum is σ = 21875208. Its totient is φ = 21875206.

The previous prime is 21875173. The next prime is 21875233. The reversal of 21875207 is 70257812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21875207 - 2⁶ = 21875143 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21875237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10937603 + 10937604.

It is an arithmetic number, because the mean of its divisors is an integer number (10937604).

Almost surely, 2^21875207 is an apocalyptic number.

21875207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21875207 is an equidigital number, since it uses as much as digits as its factorization.

21875207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 21875207 is about 4677.0938626459. The cubic root of 21875207 is about 279.6731176837.

The spelling of 21875207 in words is "twenty-one million, eight hundred seventy-five thousand, two hundred seven".