21010231 has 8 divisors (see below), whose sum is σ = 22984704. Its totient is φ = 19046520.

The previous prime is 21010229. The next prime is 21010237. The reversal of 21010231 is 13201012.

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 21010231 - 2¹ = 21010229 is a prime.

It is a super-2 number, since 2×21010231² = 882859613346722, 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 (21010237) 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, 1720 + ... + 6706.

It is an arithmetic number, because the mean of its divisors is an integer number (2873088).

Almost surely, 2^21010231 is an apocalyptic number.

21010231 is a deficient number, since it is larger than the sum of its proper divisors (1974473).

21010231 is a wasteful number, since it uses less digits than its factorization.

21010231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5381.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21010231 is about 4583.6918526445. The cubic root of 21010231 is about 275.9372144168.

Adding to 21010231 its reverse (13201012), we get a palindrome (34211243).

The spelling of 21010231 in words is "twenty-one million, ten thousand, two hundred thirty-one".