21741389 has 2 divisors, whose sum is σ = 21741390. Its totient is φ = 21741388.

The previous prime is 21741373. The next prime is 21741397. The reversal of 21741389 is 98314712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11276164 + 10465225 = 3358^2 + 3235^2 .

It is a cyclic number.

It is not a de Polignac number, because 21741389 - 2⁴ = 21741373 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21741319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10870694 + 10870695.

It is an arithmetic number, because the mean of its divisors is an integer number (10870695).

Almost surely, 2^21741389 is an apocalyptic number.

It is an amenable number.

21741389 is a deficient number, since it is larger than the sum of its proper divisors (1).

21741389 is an equidigital number, since it uses as much as digits as its factorization.

21741389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 21741389 is about 4662.7662390474. The cubic root of 21741389 is about 279.1016659932.

The spelling of 21741389 in words is "twenty-one million, seven hundred forty-one thousand, three hundred eighty-nine".