21873331 has 2 divisors, whose sum is σ = 21873332. Its totient is φ = 21873330.

The previous prime is 21873311. The next prime is 21873343. The reversal of 21873331 is 13337812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21873331 - 2¹⁹ = 21349043 is a prime.

It is a super-2 number, since 2×21873331² = 956885218071122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21873331.

It is not a weakly prime, because it can be changed into another prime (21873311) 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, 10936665 + 10936666.

It is an arithmetic number, because the mean of its divisors is an integer number (10936666).

Almost surely, 2^21873331 is an apocalyptic number.

21873331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21873331 is an equidigital number, since it uses as much as digits as its factorization.

21873331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 21873331 is about 4676.8933064589. The cubic root of 21873331 is about 279.6651226086.

The spelling of 21873331 in words is "twenty-one million, eight hundred seventy-three thousand, three hundred thirty-one".