21745194 has 16 divisors (see below), whose sum is σ = 43834368. Its totient is φ = 7191072.

The previous prime is 21745187. The next prime is 21745201. The reversal of 21745194 is 49154712.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21745187) and next prime (21745201).

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, 13507 + ... + 15030.

It is an arithmetic number, because the mean of its divisors is an integer number (2739648).

Almost surely, 2^21745194 is an apocalyptic number.

21745194 is an abundant number, since it is smaller than the sum of its proper divisors (22089174).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21745194 is a wasteful number, since it uses less digits than its factorization.

21745194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28669.

The product of its digits is 10080, while the sum is 33.

The square root of 21745194 is about 4663.1742407935. The cubic root of 21745194 is about 279.1179470734.

The spelling of 21745194 in words is "twenty-one million, seven hundred forty-five thousand, one hundred ninety-four".