21371800 has 24 divisors (see below), whose sum is σ = 49689900. Its totient is φ = 8548640.

The previous prime is 21371797. The next prime is 21371809. The reversal of 21371800 is 817312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 53230 + ... + 53629.

Almost surely, 2^21371800 is an apocalyptic number.

21371800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21371800 is an abundant number, since it is smaller than the sum of its proper divisors (28318100).

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

21371800 is a wasteful number, since it uses less digits than its factorization.

21371800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106875 (or 106866 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 21371800 is about 4622.9644169083. The cubic root of 21371800 is about 277.5111052559.

The spelling of 21371800 in words is "twenty-one million, three hundred seventy-one thousand, eight hundred".