21049100 has 18 divisors (see below), whose sum is σ = 45676764. Its totient is φ = 8419600.

The previous prime is 21049027. The next prime is 21049103. The reversal of 21049100 is 194012.

It is a happy number.

It is a super-3 number, since 3×21049100³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21049103) 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, 105146 + ... + 105345.

It is an arithmetic number, because the mean of its divisors is an integer number (2537598).

Almost surely, 2^21049100 is an apocalyptic number.

21049100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21049100 is an abundant number, since it is smaller than the sum of its proper divisors (24627664).

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

21049100 is a wasteful number, since it uses less digits than its factorization.

21049100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210505 (or 210498 counting only the distinct ones).

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

The square root of 21049100 is about 4587.9298163769. The cubic root of 21049100 is about 276.1072711916.

The spelling of 21049100 in words is "twenty-one million, forty-nine thousand, one hundred".