21831293 has 8 divisors (see below), whose sum is σ = 24152256. Its totient is φ = 19566400.

The previous prime is 21831263. The next prime is 21831353. The reversal of 21831293 is 39213812.

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 21831293 - 2¹⁰ = 21830269 is a prime.

It is a super-3 number, since 3×21831293³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21831253) 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, 13196 + ... + 14757.

It is an arithmetic number, because the mean of its divisors is an integer number (3019032).

Almost surely, 2^21831293 is an apocalyptic number.

It is an amenable number.

21831293 is a deficient number, since it is larger than the sum of its proper divisors (2320963).

21831293 is a wasteful number, since it uses less digits than its factorization.

21831293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28035.

The product of its digits is 2592, while the sum is 29.

The square root of 21831293 is about 4672.3969223515. The cubic root of 21831293 is about 279.4858464228.

The spelling of 21831293 in words is "twenty-one million, eight hundred thirty-one thousand, two hundred ninety-three".