21199597 has 8 divisors (see below), whose sum is σ = 21503232. Its totient is φ = 20898000.

The previous prime is 21199579. The next prime is 21199603. The reversal of 21199597 is 79599112.

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

It is a cyclic number.

It is not a de Polignac number, because 21199597 - 2¹⁹ = 20675309 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 (21199547) 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, 43288 + ... + 43774.

It is an arithmetic number, because the mean of its divisors is an integer number (2687904).

Almost surely, 2^21199597 is an apocalyptic number.

It is an amenable number.

21199597 is a deficient number, since it is larger than the sum of its proper divisors (303635).

21199597 is a wasteful number, since it uses less digits than its factorization.

21199597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1019.

The product of its digits is 51030, while the sum is 43.

The square root of 21199597 is about 4604.3020100771. The cubic root of 21199597 is about 276.7637469993.

The spelling of 21199597 in words is "twenty-one million, one hundred ninety-nine thousand, five hundred ninety-seven".