21090341 has 2 divisors, whose sum is σ = 21090342. Its totient is φ = 21090340.

The previous prime is 21090299. The next prime is 21090347. The reversal of 21090341 is 14309012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16638241 + 4452100 = 4079^2 + 2110^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21090341 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21090347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10545170 + 10545171.

It is an arithmetic number, because the mean of its divisors is an integer number (10545171).

Almost surely, 2^21090341 is an apocalyptic number.

It is an amenable number.

21090341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21090341 is an equidigital number, since it uses as much as digits as its factorization.

21090341 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21090341 is about 4592.4221278101. The cubic root of 21090341 is about 276.2874770173.

Adding to 21090341 its reverse (14309012), we get a palindrome (35399353).

The spelling of 21090341 in words is "twenty-one million, ninety thousand, three hundred forty-one".