21989194 has 16 divisors (see below), whose sum is σ = 36763200. Its totient is φ = 9802944.

The previous prime is 21989183. The next prime is 21989203. The reversal of 21989194 is 49198912.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21989194.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16374 + ... + 17665.

It is an arithmetic number, because the mean of its divisors is an integer number (2297700).

Almost surely, 2^21989194 is an apocalyptic number.

21989194 is a deficient number, since it is larger than the sum of its proper divisors (14774006).

21989194 is a wasteful number, since it uses less digits than its factorization.

21989194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34077.

The product of its digits is 46656, while the sum is 43.

The square root of 21989194 is about 4689.2636948672. The cubic root of 21989194 is about 280.1580485264.

The spelling of 21989194 in words is "twenty-one million, nine hundred eighty-nine thousand, one hundred ninety-four".