21894667 has 2 divisors, whose sum is σ = 21894668. Its totient is φ = 21894666.

The previous prime is 21894647. The next prime is 21894683. The reversal of 21894667 is 76649812.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21894667 is a prime.

It is not a weakly prime, because it can be changed into another prime (21894617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10947333 + 10947334.

It is an arithmetic number, because the mean of its divisors is an integer number (10947334).

Almost surely, 2^21894667 is an apocalyptic number.

21894667 is a deficient number, since it is larger than the sum of its proper divisors (1).

21894667 is an equidigital number, since it uses as much as digits as its factorization.

21894667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 43.

The square root of 21894667 is about 4679.1737518498. The cubic root of 21894667 is about 279.7560247212.

The spelling of 21894667 in words is "twenty-one million, eight hundred ninety-four thousand, six hundred sixty-seven".