21395385 has 24 divisors (see below), whose sum is σ = 40457664. Its totient is φ = 10373280.

The previous prime is 21395383. The next prime is 21395393. The reversal of 21395385 is 58359312.

It is not a de Polignac number, because 21395385 - 2¹ = 21395383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21395383) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21117 + ... + 22106.

It is an arithmetic number, because the mean of its divisors is an integer number (1685736).

Almost surely, 2^21395385 is an apocalyptic number.

It is an amenable number.

21395385 is a deficient number, since it is larger than the sum of its proper divisors (19062279).

21395385 is a wasteful number, since it uses less digits than its factorization.

21395385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43245 (or 43242 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 21395385 is about 4625.5145659699. The cubic root of 21395385 is about 277.6131508372.

The spelling of 21395385 in words is "twenty-one million, three hundred ninety-five thousand, three hundred eighty-five".