21113580 has 48 divisors (see below), whose sum is σ = 59369184. Its totient is φ = 5606400.

The previous prime is 21113549. The next prime is 21113581. The reversal of 21113580 is 8531112.

It is not an unprimeable number, because it can be changed into a prime (21113581) 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 15 ways as a sum of consecutive naturals, for example, 16980 + ... + 18180.

It is an arithmetic number, because the mean of its divisors is an integer number (1236858).

Almost surely, 2^21113580 is an apocalyptic number.

21113580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113580 is an abundant number, since it is smaller than the sum of its proper divisors (38255604).

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

21113580 is a wasteful number, since it uses less digits than its factorization.

21113580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1506 (or 1504 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 21113580 is about 4594.9515775468. The cubic root of 21113580 is about 276.3889182073.

Adding to 21113580 its reverse (8531112), we get a palindrome (29644692).

The spelling of 21113580 in words is "twenty-one million, one hundred thirteen thousand, five hundred eighty".