21874231 has 8 divisors (see below), whose sum is σ = 22460480.
Its totient is φ = 21295872.
The previous prime is 21874199. The next prime is 21874241. The reversal of 21874231 is 13247812.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 21874231 - 25 = 21874199 is a prime.
It is a super-2 number, since 2×218742312 = 956963963682722, which contains 22 as substring.
It is a Duffinian number.
It is a self number, because there is not a number n which added to its sum of digits gives 21874231.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (21874241) 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, 3871 + ... + 7663.
It is an arithmetic number, because the mean of its divisors is an integer number (2807560).
Almost surely, 221874231 is an apocalyptic number.
21874231 is a deficient number, since it is larger than the sum of its proper divisors (586249).
21874231 is an equidigital number, since it uses as much as digits as its factorization.
21874231 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3945.
The product of its digits is 2688, while the sum is 28.
The square root of 21874231 is about 4676.9895231869.
The cubic root of 21874231 is about 279.6689582561.
The spelling of 21874231 in words is "twenty-one million, eight hundred seventy-four thousand, two hundred thirty-one".