21310231 has 8 divisors (see below), whose sum is σ = 22619520. Its totient is φ = 20007168.

The previous prime is 21310207. The next prime is 21310243. The reversal of 21310231 is 13201312.

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 21310231 - 2⁵ = 21310199 is a prime.

It is a super-2 number, since 2×21310231² = 908251890546722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310271) 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, 6835 + ... + 9451.

It is an arithmetic number, because the mean of its divisors is an integer number (2827440).

Almost surely, 2^21310231 is an apocalyptic number.

21310231 is a deficient number, since it is larger than the sum of its proper divisors (1309289).

21310231 is a wasteful number, since it uses less digits than its factorization.

21310231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3113.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21310231 is about 4616.3005751359. The cubic root of 21310231 is about 277.2443594344.

Adding to 21310231 its reverse (13201312), we get a palindrome (34511543).

The spelling of 21310231 in words is "twenty-one million, three hundred ten thousand, two hundred thirty-one".