21130300 has 36 divisors (see below), whose sum is σ = 46231416. Its totient is φ = 8382400.

The previous prime is 21130279. The next prime is 21130301. The reversal of 21130300 is 303112.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130301) 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 11 ways as a sum of consecutive naturals, for example, 12294 + ... + 13906.

It is an arithmetic number, because the mean of its divisors is an integer number (1284206).

Almost surely, 2^21130300 is an apocalyptic number.

21130300 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21130300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23115708).

21130300 is an abundant number, since it is smaller than the sum of its proper divisors (25101116).

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

21130300 is a wasteful number, since it uses less digits than its factorization.

21130300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1758 (or 1751 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 10.

The square root of 21130300 is about 4596.7706055447. The cubic root of 21130300 is about 276.4618570992.

Adding to 21130300 its reverse (303112), we get a palindrome (21433412).

It can be divided in two parts, 21 and 130300, that added together give a 4-th power (130321 = 19⁴).

The spelling of 21130300 in words is "twenty-one million, one hundred thirty thousand, three hundred".