21867533 has 2 divisors, whose sum is σ = 21867534. Its totient is φ = 21867532.

The previous prime is 21867523. The next prime is 21867539. The reversal of 21867533 is 33576812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21696964 + 170569 = 4658^2 + 413^2 .

It is a cyclic number.

It is not a de Polignac number, because 21867533 - 2⁸ = 21867277 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21867493 and 21867502.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21867539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10933766 + 10933767.

It is an arithmetic number, because the mean of its divisors is an integer number (10933767).

Almost surely, 2^21867533 is an apocalyptic number.

It is an amenable number.

21867533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21867533 is an equidigital number, since it uses as much as digits as its factorization.

21867533 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 35.

The square root of 21867533 is about 4676.2734094576. The cubic root of 21867533 is about 279.6404099929.

The spelling of 21867533 in words is "twenty-one million, eight hundred sixty-seven thousand, five hundred thirty-three".