21268567 has 2 divisors, whose sum is σ = 21268568. Its totient is φ = 21268566.

The previous prime is 21268553. The next prime is 21268579. The reversal of 21268567 is 76586212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21268567 - 2¹¹ = 21266519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21268517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10634283 + 10634284.

It is an arithmetic number, because the mean of its divisors is an integer number (10634284).

Almost surely, 2^21268567 is an apocalyptic number.

21268567 is a deficient number, since it is larger than the sum of its proper divisors (1).

21268567 is an equidigital number, since it uses as much as digits as its factorization.

21268567 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 37.

The square root of 21268567 is about 4611.7856628425. The cubic root of 21268567 is about 277.0635598128.

The spelling of 21268567 in words is "twenty-one million, two hundred sixty-eight thousand, five hundred sixty-seven".