21973807 has 2 divisors, whose sum is σ = 21973808. Its totient is φ = 21973806.

The previous prime is 21973801. The next prime is 21973813. The reversal of 21973807 is 70837912.

It is a balanced prime because it is at equal distance from previous prime (21973801) and next prime (21973813).

It is a cyclic number.

It is not a de Polignac number, because 21973807 - 2³ = 21973799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21973801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10986903 + 10986904.

It is an arithmetic number, because the mean of its divisors is an integer number (10986904).

Almost surely, 2^21973807 is an apocalyptic number.

21973807 is a deficient number, since it is larger than the sum of its proper divisors (1).

21973807 is an equidigital number, since it uses as much as digits as its factorization.

21973807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 21973807 is about 4687.6227450596. The cubic root of 21973807 is about 280.0926861522.

The spelling of 21973807 in words is "twenty-one million, nine hundred seventy-three thousand, eight hundred seven".