131221760 has 72 divisors (see below), whose sum is σ = 324554496. Its totient is φ = 50780160.

The previous prime is 131221757. The next prime is 131221763. The reversal of 131221760 is 67122131.

It is an interprime number because it is at equal distance from previous prime (131221757) and next prime (131221763).

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131221763) 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, 38027 + ... + 41333.

Almost surely, 2^131221760 is an apocalyptic number.

131221760 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

131221760 is the 6614-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 131221760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162277248).

131221760 is an abundant number, since it is smaller than the sum of its proper divisors (193332736).

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

131221760 is an equidigital number, since it uses as much as digits as its factorization.

131221760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3359 (or 3345 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 131221760 is about 11455.2066764419. The cubic root of 131221760 is about 508.1617274970.

Adding to 131221760 its reverse (67122131), we get a palindrome (198343891).

The spelling of 131221760 in words is "one hundred thirty-one million, two hundred twenty-one thousand, seven hundred sixty".