21027206 has 4 divisors (see below), whose sum is σ = 31540812. Its totient is φ = 10513602.

The previous prime is 21027179. The next prime is 21027239. The reversal of 21027206 is 60272012.

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, 5256800 + ... + 5256803.

It is an arithmetic number, because the mean of its divisors is an integer number (7885203).

Almost surely, 2^21027206 is an apocalyptic number.

21027206 is a deficient number, since it is larger than the sum of its proper divisors (10513606).

21027206 is a wasteful number, since it uses less digits than its factorization.

21027206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10513605.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21027206 is about 4585.5431521249. The cubic root of 21027206 is about 276.0115079568.

Adding to 21027206 its reverse (60272012), we get a palindrome (81299218).

The spelling of 21027206 in words is "twenty-one million, twenty-seven thousand, two hundred six".