21333967 has 2 divisors, whose sum is σ = 21333968. Its totient is φ = 21333966.

The previous prime is 21333947. The next prime is 21333971. The reversal of 21333967 is 76933312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21333967 - 2⁷ = 21333839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21333947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666983 + 10666984.

It is an arithmetic number, because the mean of its divisors is an integer number (10666984).

Almost surely, 2^21333967 is an apocalyptic number.

21333967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21333967 is an equidigital number, since it uses as much as digits as its factorization.

21333967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 34.

The square root of 21333967 is about 4618.8707494365. The cubic root of 21333967 is about 277.3472557126.

The spelling of 21333967 in words is "twenty-one million, three hundred thirty-three thousand, nine hundred sixty-seven".