21884437 has 2 divisors, whose sum is σ = 21884438. Its totient is φ = 21884436.

The previous prime is 21884417. The next prime is 21884441. The reversal of 21884437 is 73448812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16982641 + 4901796 = 4121^2 + 2214^2 .

It is a cyclic number.

It is not a de Polignac number, because 21884437 - 2¹⁹ = 21360149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21884396 and 21884405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21884417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10942218 + 10942219.

It is an arithmetic number, because the mean of its divisors is an integer number (10942219).

Almost surely, 2^21884437 is an apocalyptic number.

It is an amenable number.

21884437 is a deficient number, since it is larger than the sum of its proper divisors (1).

21884437 is an equidigital number, since it uses as much as digits as its factorization.

21884437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43008, while the sum is 37.

The square root of 21884437 is about 4678.0804824201. The cubic root of 21884437 is about 279.7124471386.

The spelling of 21884437 in words is "twenty-one million, eight hundred eighty-four thousand, four hundred thirty-seven".