21301320 has 32 divisors (see below), whose sum is σ = 63904320. Its totient is φ = 5680320.

The previous prime is 21301279. The next prime is 21301321. The reversal of 21301320 is 2310312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21301296 and 21301305.

It is not an unprimeable number, because it can be changed into a prime (21301321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88636 + ... + 88875.

It is an arithmetic number, because the mean of its divisors is an integer number (1997010).

Almost surely, 2^21301320 is an apocalyptic number.

21301320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21301320 is an abundant number, since it is smaller than the sum of its proper divisors (42603000).

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

21301320 is a wasteful number, since it uses less digits than its factorization.

21301320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177525 (or 177521 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 21301320 is about 4615.3353074289. The cubic root of 21301320 is about 277.2057102534.

Adding to 21301320 its reverse (2310312), we get a palindrome (23611632).

The spelling of 21301320 in words is "twenty-one million, three hundred one thousand, three hundred twenty".