21087206 has 8 divisors (see below), whose sum is σ = 36149520. Its totient is φ = 9037368.

The previous prime is 21087203. The next prime is 21087211. The reversal of 21087206 is 60278012.

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 (21087203) 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, 753101 + ... + 753128.

It is an arithmetic number, because the mean of its divisors is an integer number (4518690).

Almost surely, 2^21087206 is an apocalyptic number.

21087206 is a deficient number, since it is larger than the sum of its proper divisors (15062314).

21087206 is a wasteful number, since it uses less digits than its factorization.

21087206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506238.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21087206 is about 4592.0807919722. The cubic root of 21087206 is about 276.2737866402.

The spelling of 21087206 in words is "twenty-one million, eighty-seven thousand, two hundred six".