21362820 has 48 divisors (see below), whose sum is σ = 60023040. Its totient is φ = 5677056.

The previous prime is 21362753. The next prime is 21362827. The reversal of 21362820 is 2826312.

It is not an unprimeable number, because it can be changed into a prime (21362827) 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 15 ways as a sum of consecutive naturals, for example, 27396 + ... + 28164.

It is an arithmetic number, because the mean of its divisors is an integer number (1250480).

Almost surely, 2^21362820 is an apocalyptic number.

21362820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21362820 is an abundant number, since it is smaller than the sum of its proper divisors (38660220).

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

21362820 is a wasteful number, since it uses less digits than its factorization.

21362820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1244 (or 1242 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21362820 is about 4621.9930765850. The cubic root of 21362820 is about 277.4722316180.

The spelling of 21362820 in words is "twenty-one million, three hundred sixty-two thousand, eight hundred twenty".