21013100 has 18 divisors (see below), whose sum is σ = 45598644. Its totient is φ = 8405200.

The previous prime is 21013093. The next prime is 21013103. The reversal of 21013100 is 131012.

It is a super-2 number, since 2×21013100² = 883100743220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21013103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 104966 + ... + 105165.

It is an arithmetic number, because the mean of its divisors is an integer number (2533258).

Almost surely, 2^21013100 is an apocalyptic number.

21013100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21013100 is an abundant number, since it is smaller than the sum of its proper divisors (24585544).

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

21013100 is a wasteful number, since it uses less digits than its factorization.

21013100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210145 (or 210138 counting only the distinct ones).

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

The square root of 21013100 is about 4584.0047992994. The cubic root of 21013100 is about 275.9497738192.

Adding to 21013100 its reverse (131012), we get a palindrome (21144112).

The spelling of 21013100 in words is "twenty-one million, thirteen thousand, one hundred".