21994867 has 2 divisors, whose sum is σ = 21994868. Its totient is φ = 21994866.

The previous prime is 21994849. The next prime is 21994897. The reversal of 21994867 is 76849912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21994867 - 2¹¹ = 21992819 is a prime.

It is not a weakly prime, because it can be changed into another prime (21994807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10997433 + 10997434.

It is an arithmetic number, because the mean of its divisors is an integer number (10997434).

Almost surely, 2^21994867 is an apocalyptic number.

21994867 is a deficient number, since it is larger than the sum of its proper divisors (1).

21994867 is an equidigital number, since it uses as much as digits as its factorization.

21994867 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 21994867 is about 4689.8685482644. The cubic root of 21994867 is about 280.1821391464.

The spelling of 21994867 in words is "twenty-one million, nine hundred ninety-four thousand, eight hundred sixty-seven".