21103394 has 16 divisors (see below), whose sum is σ = 35013048. Its totient is φ = 9476352.

The previous prime is 21103393. The next prime is 21103403. The reversal of 21103394 is 49330112.

It can be written as a sum of positive squares in 4 ways, for example, as 15405625 + 5697769 = 3925^2 + 2387^2 .

It is not an unprimeable number, because it can be changed into a prime (21103391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10007 + ... + 11930.

Almost surely, 2^21103394 is an apocalyptic number.

21103394 is a deficient number, since it is larger than the sum of its proper divisors (13909654).

21103394 is a wasteful number, since it uses less digits than its factorization.

21103394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21989.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21103394 is about 4593.8430534793. The cubic root of 21103394 is about 276.3444641895.

The spelling of 21103394 in words is "twenty-one million, one hundred three thousand, three hundred ninety-four".