21023047 has 2 divisors, whose sum is σ = 21023048. Its totient is φ = 21023046.

The previous prime is 21023017. The next prime is 21023077. The reversal of 21023047 is 74032012.

It is a balanced prime because it is at equal distance from previous prime (21023017) and next prime (21023077).

It is a cyclic number.

It is not a de Polignac number, because 21023047 - 2²³ = 12634439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21023017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511523 + 10511524.

It is an arithmetic number, because the mean of its divisors is an integer number (10511524).

Almost surely, 2^21023047 is an apocalyptic number.

21023047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21023047 is an equidigital number, since it uses as much as digits as its factorization.

21023047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 21023047 is about 4585.0896392546. The cubic root of 21023047 is about 275.9933091916.

Adding to 21023047 its reverse (74032012), we get a palindrome (95055059).

The spelling of 21023047 in words is "twenty-one million, twenty-three thousand, forty-seven".