21394443 has 16 divisors (see below), whose sum is σ = 32970240. Its totient is φ = 12086976.

The previous prime is 21394427. The next prime is 21394453. The reversal of 21394443 is 34449312.

It is not a de Polignac number, because 21394443 - 2⁴ = 21394427 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21394443.

It is not an unprimeable number, because it can be changed into a prime (21394453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3855 + ... + 7592.

It is an arithmetic number, because the mean of its divisors is an integer number (2060640).

Almost surely, 2^21394443 is an apocalyptic number.

21394443 is a deficient number, since it is larger than the sum of its proper divisors (11575797).

21394443 is a wasteful number, since it uses less digits than its factorization.

21394443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11546.

The product of its digits is 10368, while the sum is 30.

The square root of 21394443 is about 4625.4127383402. The cubic root of 21394443 is about 277.6090765095.

The spelling of 21394443 in words is "twenty-one million, three hundred ninety-four thousand, four hundred forty-three".