131221210 has 16 divisors (see below), whose sum is σ = 246468096. Its totient is φ = 50206288.

The previous prime is 131221193. The next prime is 131221213. The reversal of 131221210 is 12122131.

131221210 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (131221213) 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, 285034 + ... + 285493.

It is an arithmetic number, because the mean of its divisors is an integer number (15404256).

Almost surely, 2^131221210 is an apocalyptic number.

131221210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

131221210 is a deficient number, since it is larger than the sum of its proper divisors (115246886).

131221210 is a wasteful number, since it uses less digits than its factorization.

131221210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570557.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 131221210 is about 11455.1826698661. The cubic root of 131221210 is about 508.1610175300.

Adding to 131221210 its reverse (12122131), we get a palindrome (143343341).

It can be divided in two parts, 1312 and 21210, that added together give a palindrome (22522).

The spelling of 131221210 in words is "one hundred thirty-one million, two hundred twenty-one thousand, two hundred ten".