21321967 has 2 divisors, whose sum is σ = 21321968. Its totient is φ = 21321966.

The previous prime is 21321959. The next prime is 21321977. The reversal of 21321967 is 76912312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21321967 - 2³ = 21321959 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21321917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660983 + 10660984.

It is an arithmetic number, because the mean of its divisors is an integer number (10660984).

Almost surely, 2^21321967 is an apocalyptic number.

21321967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321967 is an equidigital number, since it uses as much as digits as its factorization.

21321967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 31.

The square root of 21321967 is about 4617.5715479026. The cubic root of 21321967 is about 277.2952448938.

The spelling of 21321967 in words is "twenty-one million, three hundred twenty-one thousand, nine hundred sixty-seven".