21300381 has 8 divisors (see below), whose sum is σ = 31556160. Its totient is φ = 14200236.

The previous prime is 21300359. The next prime is 21300401. The reversal of 21300381 is 18300312.

It is not a de Polignac number, because 21300381 - 2¹³ = 21292189 is a prime.

It is a super-2 number, since 2×21300381² = 907412461490322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 394425 + ... + 394478.

It is an arithmetic number, because the mean of its divisors is an integer number (3944520).

Almost surely, 2^21300381 is an apocalyptic number.

It is an amenable number.

21300381 is a deficient number, since it is larger than the sum of its proper divisors (10255779).

21300381 is an equidigital number, since it uses as much as digits as its factorization.

21300381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 788912 (or 788906 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21300381 is about 4615.2335802210. The cubic root of 21300381 is about 277.2016369537.

Adding to 21300381 its reverse (18300312), we get a palindrome (39600693).

The spelling of 21300381 in words is "twenty-one million, three hundred thousand, three hundred eighty-one".