131221230 has 96 divisors (see below), whose sum is σ = 373261824. Its totient is φ = 28920192.

The previous prime is 131221229. The next prime is 131221231. The reversal of 131221230 is 32122131.

It is an interprime number because it is at equal distance from previous prime (131221229) and next prime (131221231).

It is a super-2 number, since 2×131221230² = 34438022405425800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131221231) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 176239 + ... + 176981.

It is an arithmetic number, because the mean of its divisors is an integer number (3888144).

Almost surely, 2^131221230 is an apocalyptic number.

131221230 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 131221230, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (186630912).

131221230 is an abundant number, since it is smaller than the sum of its proper divisors (242040594).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131221230 is a wasteful number, since it uses less digits than its factorization.

131221230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818 (or 789 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 131221230 is about 11455.1835428333. The cubic root of 131221230 is about 508.1610433471.

Adding to 131221230 its reverse (32122131), we get a palindrome (163343361).

Subtracting from 131221230 its reverse (32122131), we obtain a palindrome (99099099).

The spelling of 131221230 in words is "one hundred thirty-one million, two hundred twenty-one thousand, two hundred thirty".