21741869 has 2 divisors, whose sum is σ = 21741870. Its totient is φ = 21741868.

The previous prime is 21741847. The next prime is 21741887. The reversal of 21741869 is 96814712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21501769 + 240100 = 4637^2 + 490^2 .

It is a cyclic number.

It is not a de Polignac number, because 21741869 - 2⁸ = 21741613 is a prime.

It is a super-2 number, since 2×21741869² = 945417735226322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21741469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10870934 + 10870935.

It is an arithmetic number, because the mean of its divisors is an integer number (10870935).

Almost surely, 2^21741869 is an apocalyptic number.

It is an amenable number.

21741869 is a deficient number, since it is larger than the sum of its proper divisors (1).

21741869 is an equidigital number, since it uses as much as digits as its factorization.

21741869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 38.

The square root of 21741869 is about 4662.8177103550. The cubic root of 21741869 is about 279.1037199530.

The spelling of 21741869 in words is "twenty-one million, seven hundred forty-one thousand, eight hundred sixty-nine".