21695903 has 2 divisors, whose sum is σ = 21695904. Its totient is φ = 21695902.

The previous prime is 21695897. The next prime is 21695917. The reversal of 21695903 is 30959612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21695903 - 2²² = 17501599 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21695953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10847951 + 10847952.

It is an arithmetic number, because the mean of its divisors is an integer number (10847952).

Almost surely, 2^21695903 is an apocalyptic number.

21695903 is a deficient number, since it is larger than the sum of its proper divisors (1).

21695903 is an equidigital number, since it uses as much as digits as its factorization.

21695903 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 21695903 is about 4657.8861085261. The cubic root of 21695903 is about 278.9068903042.

The spelling of 21695903 in words is "twenty-one million, six hundred ninety-five thousand, nine hundred three".