21867047 has 2 divisors, whose sum is σ = 21867048. Its totient is φ = 21867046.

The previous prime is 21867023. The next prime is 21867067. The reversal of 21867047 is 74076812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21867047 - 2¹⁶ = 21801511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21866998 and 21867016.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21867067) 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, 10933523 + 10933524.

It is an arithmetic number, because the mean of its divisors is an integer number (10933524).

Almost surely, 2^21867047 is an apocalyptic number.

21867047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21867047 is an equidigital number, since it uses as much as digits as its factorization.

21867047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 21867047 is about 4676.2214447137. The cubic root of 21867047 is about 279.6383383334.

The spelling of 21867047 in words is "twenty-one million, eight hundred sixty-seven thousand, forty-seven".