21250030 has 16 divisors (see below), whose sum is σ = 38899440. Its totient is φ = 8355712.

The previous prime is 21250007. The next prime is 21250039. The reversal of 21250030 is 3005212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250039) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17419 + ... + 18598.

It is an arithmetic number, because the mean of its divisors is an integer number (2431215).

Almost surely, 2^21250030 is an apocalyptic number.

21250030 is a deficient number, since it is larger than the sum of its proper divisors (17649410).

21250030 is a wasteful number, since it uses less digits than its factorization.

21250030 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36083.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 21250030 is about 4609.7754826022. The cubic root of 21250030 is about 276.9830431826.

Adding to 21250030 its reverse (3005212), we get a palindrome (24255242).

The spelling of 21250030 in words is "twenty-one million, two hundred fifty thousand, thirty".