21845130 has 32 divisors (see below), whose sum is σ = 53547264. Its totient is φ = 5701056.

The previous prime is 21845113. The next prime is 21845179. The reversal of 21845130 is 3154812.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21845130.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 6337 + ... + 9156.

It is an arithmetic number, because the mean of its divisors is an integer number (1673352).

Almost surely, 2^21845130 is an apocalyptic number.

21845130 is an abundant number, since it is smaller than the sum of its proper divisors (31702134).

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

21845130 is a wasteful number, since it uses less digits than its factorization.

21845130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15550.

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

The square root of 21845130 is about 4673.8774053242. The cubic root of 21845130 is about 279.5448813886.

Adding to 21845130 its reverse (3154812), we get a palindrome (24999942).

The spelling of 21845130 in words is "twenty-one million, eight hundred forty-five thousand, one hundred thirty".