21355100 has 36 divisors (see below), whose sum is σ = 49908264. Its totient is φ = 7884480.

The previous prime is 21355097. The next prime is 21355121. The reversal of 21355100 is 155312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6914 + ... + 9513.

Almost surely, 2^21355100 is an apocalyptic number.

21355100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21355100 is an abundant number, since it is smaller than the sum of its proper divisors (28553164).

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

21355100 is a wasteful number, since it uses less digits than its factorization.

21355100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16454 (or 16447 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 21355100 is about 4621.1578635662. The cubic root of 21355100 is about 277.4388037011.

The spelling of 21355100 in words is "twenty-one million, three hundred fifty-five thousand, one hundred".