21941489 has 2 divisors, whose sum is σ = 21941490. Its totient is φ = 21941488.

The previous prime is 21941461. The next prime is 21941501. The reversal of 21941489 is 98414912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17808400 + 4133089 = 4220^2 + 2033^2 .

It is a cyclic number.

It is not a de Polignac number, because 21941489 - 2⁸ = 21941233 is a prime.

It is not a weakly prime, because it can be changed into another prime (21941449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10970744 + 10970745.

It is an arithmetic number, because the mean of its divisors is an integer number (10970745).

Almost surely, 2^21941489 is an apocalyptic number.

It is an amenable number.

21941489 is a deficient number, since it is larger than the sum of its proper divisors (1).

21941489 is an equidigital number, since it uses as much as digits as its factorization.

21941489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 21941489 is about 4684.1743135797. The cubic root of 21941489 is about 279.9553032395.

It can be divided in two parts, 2 and 1941489, that added together give a palindrome (1941491).

The spelling of 21941489 in words is "twenty-one million, nine hundred forty-one thousand, four hundred eighty-nine".