21250086 has 32 divisors (see below), whose sum is σ = 49932288. Its totient is φ = 5943840.

The previous prime is 21250067. The next prime is 21250111. The reversal of 21250086 is 68005212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11526 + ... + 13241.

It is an arithmetic number, because the mean of its divisors is an integer number (1560384).

Almost surely, 2^21250086 is an apocalyptic number.

21250086 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21250086 is an abundant number, since it is smaller than the sum of its proper divisors (28682202).

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

21250086 is a wasteful number, since it uses less digits than its factorization.

21250086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24796.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 21250086 is about 4609.7815566467. The cubic root of 21250086 is about 276.9832864926.

Adding to 21250086 its reverse (68005212), we get a palindrome (89255298).

The spelling of 21250086 in words is "twenty-one million, two hundred fifty thousand, eighty-six".