21194351 has 2 divisors, whose sum is σ = 21194352. Its totient is φ = 21194350.

The previous prime is 21194333. The next prime is 21194353. The reversal of 21194351 is 15349112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21194351 - 2¹⁴ = 21177967 is a prime.

It is a super-2 number, since 2×21194351² = 898401028622402, which contains 22 as substring.

Together with 21194353, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21194351.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21194353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10597175 + 10597176.

It is an arithmetic number, because the mean of its divisors is an integer number (10597176).

Almost surely, 2^21194351 is an apocalyptic number.

21194351 is a deficient number, since it is larger than the sum of its proper divisors (1).

21194351 is an equidigital number, since it uses as much as digits as its factorization.

21194351 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 26.

The square root of 21194351 is about 4603.7322902184. The cubic root of 21194351 is about 276.7409160245.

The spelling of 21194351 in words is "twenty-one million, one hundred ninety-four thousand, three hundred fifty-one".