21302100 has 54 divisors (see below), whose sum is σ = 66773070. Its totient is φ = 5680320.

The previous prime is 21302093. The next prime is 21302111. The reversal of 21302100 is 120312.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 617796 + 20684304 = 786^2 + 4548^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 10935 + ... + 12734.

Almost surely, 2^21302100 is an apocalyptic number.

21302100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21302100 is an abundant number, since it is smaller than the sum of its proper divisors (45470970).

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

21302100 is a wasteful number, since it uses less digits than its factorization.

21302100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23689 (or 23679 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 21302100 is about 4615.4198075581. The cubic root of 21302100 is about 277.2090937341.

Adding to 21302100 its reverse (120312), we get a palindrome (21422412).

The spelling of 21302100 in words is "twenty-one million, three hundred two thousand, one hundred".