21033397 has 12 divisors (see below), whose sum is σ = 26692416. Its totient is φ = 16389240.

The previous prime is 21033391. The next prime is 21033401. The reversal of 21033397 is 79333012.

It is not a de Polignac number, because 21033397 - 2¹¹ = 21031349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033391) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18973 + ... + 20050.

It is an arithmetic number, because the mean of its divisors is an integer number (2224368).

Almost surely, 2^21033397 is an apocalyptic number.

It is an amenable number.

21033397 is a deficient number, since it is larger than the sum of its proper divisors (5659019).

21033397 is a wasteful number, since it uses less digits than its factorization.

21033397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39048 (or 39041 counting only the distinct ones).

The product of its (nonzero) digits is 3402, while the sum is 28.

The square root of 21033397 is about 4586.2181587883. The cubic root of 21033397 is about 276.0385938119.

The spelling of 21033397 in words is "twenty-one million, thirty-three thousand, three hundred ninety-seven".