21347423 has 2 divisors, whose sum is σ = 21347424. Its totient is φ = 21347422.

The previous prime is 21347419. The next prime is 21347441. The reversal of 21347423 is 32474312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21347423 - 2² = 21347419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21347392 and 21347401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21347723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10673711 + 10673712.

It is an arithmetic number, because the mean of its divisors is an integer number (10673712).

Almost surely, 2^21347423 is an apocalyptic number.

21347423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21347423 is an equidigital number, since it uses as much as digits as its factorization.

21347423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 26.

The square root of 21347423 is about 4620.3271529189. The cubic root of 21347423 is about 277.4055539860.

The spelling of 21347423 in words is "twenty-one million, three hundred forty-seven thousand, four hundred twenty-three".