21284206 has 4 divisors (see below), whose sum is σ = 31926312. Its totient is φ = 10642102.

The previous prime is 21284189. The next prime is 21284227. The reversal of 21284206 is 60248212.

It is a happy number.

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, 5321050 + ... + 5321053.

It is an arithmetic number, because the mean of its divisors is an integer number (7981578).

Almost surely, 2^21284206 is an apocalyptic number.

21284206 is a deficient number, since it is larger than the sum of its proper divisors (10642106).

21284206 is a wasteful number, since it uses less digits than its factorization.

21284206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10642105.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 21284206 is about 4613.4808984107. The cubic root of 21284206 is about 277.1314524203.

The spelling of 21284206 in words is "twenty-one million, two hundred eighty-four thousand, two hundred six".