21350231 has 12 divisors (see below), whose sum is σ = 25416072. Its totient is φ = 17872848.

The previous prime is 21350213. The next prime is 21350291. The reversal of 21350231 is 13205312.

It is not a de Polignac number, because 21350231 - 2¹⁴ = 21333847 is a prime.

It is a super-2 number, since 2×21350231² = 911664727506722, which contains 22 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 (21350201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2960 + ... + 7173.

It is an arithmetic number, because the mean of its divisors is an integer number (2118006).

Almost surely, 2^21350231 is an apocalyptic number.

21350231 is a deficient number, since it is larger than the sum of its proper divisors (4065841).

21350231 is a wasteful number, since it uses less digits than its factorization.

21350231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10190 (or 10183 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21350231 is about 4620.6310175127. The cubic root of 21350231 is about 277.4177165882.

Adding to 21350231 its reverse (13205312), we get a palindrome (34555543).

The spelling of 21350231 in words is "twenty-one million, three hundred fifty thousand, two hundred thirty-one".