21131230 has 16 divisors (see below), whose sum is σ = 40038480. Its totient is φ = 8007552.

The previous prime is 21131191. The next prime is 21131251. The reversal of 21131230 is 3213112.

It is a self number, because there is not a number n which added to its sum of digits gives 21131230.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55419 + ... + 55798.

It is an arithmetic number, because the mean of its divisors is an integer number (2502405).

Almost surely, 2^21131230 is an apocalyptic number.

21131230 is a deficient number, since it is larger than the sum of its proper divisors (18907250).

21131230 is a wasteful number, since it uses less digits than its factorization.

21131230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111243.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21131230 is about 4596.8717624054. The cubic root of 21131230 is about 276.4659129772.

Adding to 21131230 its reverse (3213112), we get a palindrome (24344342).

The spelling of 21131230 in words is "twenty-one million, one hundred thirty-one thousand, two hundred thirty".