21395331 has 6 divisors (see below), whose sum is σ = 30904380. Its totient is φ = 14263548.

The previous prime is 21395329. The next prime is 21395383. The reversal of 21395331 is 13359312.

It is a happy number.

It is not a de Polignac number, because 21395331 - 2¹ = 21395329 is a prime.

It is a super-2 number, since 2×21395331² = 915520377199122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21395295 and 21395304.

It is not an unprimeable number, because it can be changed into a prime (21395321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1188621 + ... + 1188638.

It is an arithmetic number, because the mean of its divisors is an integer number (5150730).

Almost surely, 2^21395331 is an apocalyptic number.

21395331 is a deficient number, since it is larger than the sum of its proper divisors (9509049).

21395331 is a wasteful number, since it uses less digits than its factorization.

21395331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2377265 (or 2377262 counting only the distinct ones).

The product of its digits is 2430, while the sum is 27.

The square root of 21395331 is about 4625.5087287778. The cubic root of 21395331 is about 277.6129172802.

The spelling of 21395331 in words is "twenty-one million, three hundred ninety-five thousand, three hundred thirty-one".