21995367 has 4 divisors (see below), whose sum is σ = 29327160. Its totient is φ = 14663576.

The previous prime is 21995359. The next prime is 21995387. The reversal of 21995367 is 76359912.

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 21995367 - 2³ = 21995359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21995387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3665892 + ... + 3665897.

It is an arithmetic number, because the mean of its divisors is an integer number (7331790).

Almost surely, 2^21995367 is an apocalyptic number.

21995367 is a deficient number, since it is larger than the sum of its proper divisors (7331793).

21995367 is an equidigital number, since it uses as much as digits as its factorization.

21995367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7331792.

The product of its digits is 102060, while the sum is 42.

The square root of 21995367 is about 4689.9218543596. The cubic root of 21995367 is about 280.1842622176.

The spelling of 21995367 in words is "twenty-one million, nine hundred ninety-five thousand, three hundred sixty-seven".