21297894 has 8 divisors (see below), whose sum is σ = 42595800. Its totient is φ = 7099296.

The previous prime is 21297869. The next prime is 21297907. The reversal of 21297894 is 49879212.

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

21297894 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1774819 + ... + 1774830.

It is an arithmetic number, because the mean of its divisors is an integer number (5324475).

Almost surely, 2^21297894 is an apocalyptic number.

21297894 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21297894 is a wasteful number, since it uses less digits than its factorization.

21297894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3549654.

The product of its digits is 72576, while the sum is 42.

The square root of 21297894 is about 4614.9641385389. The cubic root of 21297894 is about 277.1908479870.

The spelling of 21297894 in words is "twenty-one million, two hundred ninety-seven thousand, eight hundred ninety-four".