21861214 has 4 divisors (see below), whose sum is σ = 32791824. Its totient is φ = 10930606.

The previous prime is 21861209. The next prime is 21861221. The reversal of 21861214 is 41216812.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5465302 + ... + 5465305.

It is an arithmetic number, because the mean of its divisors is an integer number (8197956).

Almost surely, 2^21861214 is an apocalyptic number.

21861214 is a deficient number, since it is larger than the sum of its proper divisors (10930610).

21861214 is a wasteful number, since it uses less digits than its factorization.

21861214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10930609.

The product of its digits is 768, while the sum is 25.

The square root of 21861214 is about 4675.5977158006. The cubic root of 21861214 is about 279.6134717616.

The spelling of 21861214 in words is "twenty-one million, eight hundred sixty-one thousand, two hundred fourteen".