21094397 has 8 divisors (see below), whose sum is σ = 21873240. Its totient is φ = 20319040.

The previous prime is 21094393. The next prime is 21094417. The reversal of 21094397 is 79349012.

It can be written as a sum of positive squares in 4 ways, for example, as 835396 + 20259001 = 914^2 + 4501^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21094397 - 2² = 21094393 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21094391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21947 + ... + 22887.

It is an arithmetic number, because the mean of its divisors is an integer number (2734155).

Almost surely, 2^21094397 is an apocalyptic number.

It is an amenable number.

21094397 is a deficient number, since it is larger than the sum of its proper divisors (778843).

21094397 is an equidigital number, since it uses as much as digits as its factorization.

21094397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1743.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 21094397 is about 4592.8637036167. The cubic root of 21094397 is about 276.3051873391.

The spelling of 21094397 in words is "twenty-one million, ninety-four thousand, three hundred ninety-seven".