21832991 has 2 divisors, whose sum is σ = 21832992. Its totient is φ = 21832990.

The previous prime is 21832973. The next prime is 21833017. The reversal of 21832991 is 19923812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21832991 - 2¹⁸ = 21570847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21822991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10916495 + 10916496.

It is an arithmetic number, because the mean of its divisors is an integer number (10916496).

Almost surely, 2^21832991 is an apocalyptic number.

21832991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21832991 is an equidigital number, since it uses as much as digits as its factorization.

21832991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 21832991 is about 4672.5786242716. The cubic root of 21832991 is about 279.4930922093.

The spelling of 21832991 in words is "twenty-one million, eight hundred thirty-two thousand, nine hundred ninety-one".