21121349 has 2 divisors, whose sum is σ = 21121350. Its totient is φ = 21121348.

The previous prime is 21121333. The next prime is 21121363. The reversal of 21121349 is 94312112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17698849 + 3422500 = 4207^2 + 1850^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121349 - 2⁴ = 21121333 is a prime.

It is a super-2 number, since 2×21121349² = 892222767159602, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560674 + 10560675.

It is an arithmetic number, because the mean of its divisors is an integer number (10560675).

Almost surely, 2^21121349 is an apocalyptic number.

It is an amenable number.

21121349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121349 is an equidigital number, since it uses as much as digits as its factorization.

21121349 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 23.

The square root of 21121349 is about 4595.7968841105. The cubic root of 21121349 is about 276.4228142778.

The spelling of 21121349 in words is "twenty-one million, one hundred twenty-one thousand, three hundred forty-nine".