21994430 has 16 divisors (see below), whose sum is σ = 41919120. Its totient is φ = 8280192.

The previous prime is 21994421. The next prime is 21994471. The reversal of 21994430 is 3449912.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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, 64520 + ... + 64859.

It is an arithmetic number, because the mean of its divisors is an integer number (2619945).

Almost surely, 2^21994430 is an apocalyptic number.

21994430 is a deficient number, since it is larger than the sum of its proper divisors (19924690).

21994430 is a wasteful number, since it uses less digits than its factorization.

21994430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129403.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21994430 is about 4689.8219582411. The cubic root of 21994430 is about 280.1802835558.

It can be divided in two parts, 219 and 94430, that added together give a palindrome (94649).

The spelling of 21994430 in words is "twenty-one million, nine hundred ninety-four thousand, four hundred thirty".