21894967 has 2 divisors, whose sum is σ = 21894968. Its totient is φ = 21894966.

The previous prime is 21894953. The next prime is 21894991. The reversal of 21894967 is 76949812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21894967 - 2⁷ = 21894839 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21894907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10947483 + 10947484.

It is an arithmetic number, because the mean of its divisors is an integer number (10947484).

Almost surely, 2^21894967 is an apocalyptic number.

21894967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21894967 is an equidigital number, since it uses as much as digits as its factorization.

21894967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 46.

The square root of 21894967 is about 4679.2058086816. The cubic root of 21894967 is about 279.7573024512.

The spelling of 21894967 in words is "twenty-one million, eight hundred ninety-four thousand, nine hundred sixty-seven".