21166894 has 8 divisors (see below), whose sum is σ = 36286128. Its totient is φ = 9071520.

The previous prime is 21166891. The next prime is 21166903. The reversal of 21166894 is 49866112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166891) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 755947 + ... + 755974.

It is an arithmetic number, because the mean of its divisors is an integer number (4535766).

Almost surely, 2^21166894 is an apocalyptic number.

21166894 is a deficient number, since it is larger than the sum of its proper divisors (15119234).

21166894 is a wasteful number, since it uses less digits than its factorization.

21166894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1511930.

The product of its digits is 20736, while the sum is 37.

The square root of 21166894 is about 4600.7492868010. The cubic root of 21166894 is about 276.6213596556.

The spelling of 21166894 in words is "twenty-one million, one hundred sixty-six thousand, eight hundred ninety-four".