21735919 has 2 divisors, whose sum is σ = 21735920. Its totient is φ = 21735918.

The previous prime is 21735859. The next prime is 21735937. The reversal of 21735919 is 91953712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21735919 - 2²³ = 13347311 is a prime.

It is a super-2 number, since 2×21735919² = 944900349549122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21735419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10867959 + 10867960.

It is an arithmetic number, because the mean of its divisors is an integer number (10867960).

Almost surely, 2^21735919 is an apocalyptic number.

21735919 is a deficient number, since it is larger than the sum of its proper divisors (1).

21735919 is an equidigital number, since it uses as much as digits as its factorization.

21735919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17010, while the sum is 37.

The square root of 21735919 is about 4662.1796404686. The cubic root of 21735919 is about 279.0782572747.

The spelling of 21735919 in words is "twenty-one million, seven hundred thirty-five thousand, nine hundred nineteen".