21867023 has 2 divisors, whose sum is σ = 21867024. Its totient is φ = 21867022.

The previous prime is 21867019. The next prime is 21867047. The reversal of 21867023 is 32076812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21867023 - 2² = 21867019 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21867523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10933511 + 10933512.

It is an arithmetic number, because the mean of its divisors is an integer number (10933512).

Almost surely, 2^21867023 is an apocalyptic number.

21867023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21867023 is an equidigital number, since it uses as much as digits as its factorization.

21867023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 21867023 is about 4676.2188785385. The cubic root of 21867023 is about 279.6382360284.

The spelling of 21867023 in words is "twenty-one million, eight hundred sixty-seven thousand, twenty-three".