21130100 has 36 divisors (see below), whose sum is σ = 47851104. Its totient is φ = 8083680.

The previous prime is 21130079. The next prime is 21130111. The reversal of 21130100 is 103112.

It is a super-2 number, since 2×21130100² = 892962252020000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2294 + ... + 6893.

Almost surely, 2^21130100 is an apocalyptic number.

21130100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21130100 is an abundant number, since it is smaller than the sum of its proper divisors (26721004).

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

21130100 is a wasteful number, since it uses less digits than its factorization.

21130100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9224 (or 9217 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 21130100 is about 4596.7488510903. The cubic root of 21130100 is about 276.4609848518.

Adding to 21130100 its reverse (103112), we get a palindrome (21233212).

The spelling of 21130100 in words is "twenty-one million, one hundred thirty thousand, one hundred".