21083397 has 8 divisors (see below), whose sum is σ = 28333056. Its totient is φ = 13944672.

The previous prime is 21083393. The next prime is 21083399. The reversal of 21083397 is 79338012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21083397 - 2² = 21083393 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21083393) 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, 27288 + ... + 28049.

It is an arithmetic number, because the mean of its divisors is an integer number (3541632).

Almost surely, 2^21083397 is an apocalyptic number.

It is an amenable number.

21083397 is a deficient number, since it is larger than the sum of its proper divisors (7249659).

21083397 is a wasteful number, since it uses less digits than its factorization.

21083397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55467.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 21083397 is about 4591.6660375075. Note that the first 3 decimals coincide. The cubic root of 21083397 is about 276.2571511154.

The spelling of 21083397 in words is "twenty-one million, eighty-three thousand, three hundred ninety-seven".