21087202 has 8 divisors (see below), whose sum is σ = 32402412. Its totient is φ = 10286400.

The previous prime is 21087197. The next prime is 21087203. The reversal of 21087202 is 20278012.

It can be written as a sum of positive squares in 2 ways, for example, as 17986081 + 3101121 = 4241^2 + 1761^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21087203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128499 + ... + 128662.

Almost surely, 2^21087202 is an apocalyptic number.

21087202 is a deficient number, since it is larger than the sum of its proper divisors (11315210).

21087202 is a wasteful number, since it uses less digits than its factorization.

21087202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257204.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 21087202 is about 4592.0803564398. The cubic root of 21087202 is about 276.2737691716.

The spelling of 21087202 in words is "twenty-one million, eighty-seven thousand, two hundred two".