21882691 has 2 divisors, whose sum is σ = 21882692. Its totient is φ = 21882690.

The previous prime is 21882667. The next prime is 21882703. The reversal of 21882691 is 19628812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21882691 - 2¹¹ = 21880643 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21882691.

It is not a weakly prime, because it can be changed into another prime (21882611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10941345 + 10941346.

It is an arithmetic number, because the mean of its divisors is an integer number (10941346).

Almost surely, 2^21882691 is an apocalyptic number.

21882691 is a deficient number, since it is larger than the sum of its proper divisors (1).

21882691 is an equidigital number, since it uses as much as digits as its factorization.

21882691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 37.

The square root of 21882691 is about 4677.8938636955. The cubic root of 21882691 is about 279.7050082004.

The spelling of 21882691 in words is "twenty-one million, eight hundred eighty-two thousand, six hundred ninety-one".