21084250 has 96 divisors (see below), whose sum is σ = 47056464. Its totient is φ = 7040000.

The previous prime is 21084227. The next prime is 21084253. The reversal of 21084250 is 5248012.

21084250 = T₂ + T₃ + ... + T₅₀₁.

It can be written as a sum of positive squares in 8 ways, for example, as 43681 + 21040569 = 209^2 + 4587^2 .

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21084253) 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 47 ways as a sum of consecutive naturals, for example, 514230 + ... + 514270.

Almost surely, 2^21084250 is an apocalyptic number.

21084250 is an abundant number, since it is smaller than the sum of its proper divisors (25972214).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21084250 is a wasteful number, since it uses less digits than its factorization.

21084250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 21084250 is about 4591.7589222432. The cubic root of 21084250 is about 276.2608767037.

The spelling of 21084250 in words is "twenty-one million, eighty-four thousand, two hundred fifty".