21594047 has 2 divisors, whose sum is σ = 21594048. Its totient is φ = 21594046.

The previous prime is 21594031. The next prime is 21594049. The reversal of 21594047 is 74049512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21594047 - 2⁴ = 21594031 is a prime.

Together with 21594049, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21594049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10797023 + 10797024.

It is an arithmetic number, because the mean of its divisors is an integer number (10797024).

Almost surely, 2^21594047 is an apocalyptic number.

21594047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21594047 is an equidigital number, since it uses as much as digits as its factorization.

21594047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21594047 is about 4646.9395304867. The cubic root of 21594047 is about 278.4697430565.

The spelling of 21594047 in words is "twenty-one million, five hundred ninety-four thousand, forty-seven".