21097423 has 2 divisors, whose sum is σ = 21097424. Its totient is φ = 21097422.

The previous prime is 21097421. The next prime is 21097441. The reversal of 21097423 is 32479012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21097423 - 2¹ = 21097421 is a prime.

Together with 21097421, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21097391 and 21097400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21097421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10548711 + 10548712.

It is an arithmetic number, because the mean of its divisors is an integer number (10548712).

Almost surely, 2^21097423 is an apocalyptic number.

21097423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21097423 is an equidigital number, since it uses as much as digits as its factorization.

21097423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21097423 is about 4593.1931159053. The cubic root of 21097423 is about 276.3183987386.

The spelling of 21097423 in words is "twenty-one million, ninety-seven thousand, four hundred twenty-three".