21041900 has 108 divisors (see below), whose sum is σ = 52642464. Its totient is φ = 7286400.

The previous prime is 21041879. The next prime is 21041981. The reversal of 21041900 is 914012.

It is a happy number.

It is a super-2 number, since 2×21041900² = 885523111220000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 447677 + ... + 447723.

Almost surely, 2^21041900 is an apocalyptic number.

21041900 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 21041900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26321232).

21041900 is an abundant number, since it is smaller than the sum of its proper divisors (31600564).

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

21041900 is a wasteful number, since it uses less digits than its factorization.

21041900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 21041900 is about 4587.1450816385. The cubic root of 21041900 is about 276.0757860915.

Adding to 21041900 its reverse (914012), we get a palindrome (21955912).

It can be divided in two parts, 2104 and 1900, that added together give a palindrome (4004).

The spelling of 21041900 in words is "twenty-one million, forty-one thousand, nine hundred".