21216883 has 2 divisors, whose sum is σ = 21216884. Its totient is φ = 21216882.

The previous prime is 21216869. The next prime is 21216887. The reversal of 21216883 is 38861212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21216883 - 2⁵ = 21216851 is a prime.

It is a super-2 number, since 2×21216883² = 900312248471378, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21216887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10608441 + 10608442.

It is an arithmetic number, because the mean of its divisors is an integer number (10608442).

Almost surely, 2^21216883 is an apocalyptic number.

21216883 is a deficient number, since it is larger than the sum of its proper divisors (1).

21216883 is an equidigital number, since it uses as much as digits as its factorization.

21216883 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 31.

The square root of 21216883 is about 4606.1787850669. The cubic root of 21216883 is about 276.8389502905.

The spelling of 21216883 in words is "twenty-one million, two hundred sixteen thousand, eight hundred eighty-three".