231210861 has 24 divisors (see below), whose sum is σ = 363680064. Its totient is φ = 130253760.

The previous prime is 231210853. The next prime is 231210869. The reversal of 231210861 is 168012132.

It is an interprime number because it is at equal distance from previous prime (231210853) and next prime (231210869).

It is not a de Polignac number, because 231210861 - 2³ = 231210853 is a prime.

It is a super-2 number, since 2×231210861² = 106916924488722642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231210869) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 640 + ... + 21513.

It is an arithmetic number, because the mean of its divisors is an integer number (15153336).

Almost surely, 2^231210861 is an apocalyptic number.

231210861 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

231210861 is a deficient number, since it is larger than the sum of its proper divisors (132469203).

231210861 is a wasteful number, since it uses less digits than its factorization.

231210861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22241 (or 22234 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 231210861 is about 15205.6193888970. The cubic root of 231210861 is about 613.7658826186.

Adding to 231210861 its reverse (168012132), we get a palindrome (399222993).

The spelling of 231210861 in words is "two hundred thirty-one million, two hundred ten thousand, eight hundred sixty-one".