131221830 has 32 divisors (see below), whose sum is σ = 317829600. Its totient is φ = 34670592.

The previous prime is 131221823. The next prime is 131221837. The reversal of 131221830 is 38122131.

It is an interprime number because it is at equal distance from previous prime (131221823) and next prime (131221837).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 131221797 and 131221806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131221837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16795 + ... + 23334.

It is an arithmetic number, because the mean of its divisors is an integer number (9932175).

Almost surely, 2^131221830 is an apocalyptic number.

131221830 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

131221830 is an abundant number, since it is smaller than the sum of its proper divisors (186607770).

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

131221830 is a wasteful number, since it uses less digits than its factorization.

131221830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40248.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 131221830 is about 11455.2097318207. The cubic root of 131221830 is about 508.1618178563.

Adding to 131221830 its reverse (38122131), we get a palindrome (169343961).

The spelling of 131221830 in words is "one hundred thirty-one million, two hundred twenty-one thousand, eight hundred thirty".