131221455 has 8 divisors (see below), whose sum is σ = 209954352. Its totient is φ = 69984768.

The previous prime is 131221439. The next prime is 131221457. The reversal of 131221455 is 554122131.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 131221455 - 2⁴ = 131221439 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131221457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4374034 + ... + 4374063.

It is an arithmetic number, because the mean of its divisors is an integer number (26244294).

Almost surely, 2^131221455 is an apocalyptic number.

131221455 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

131221455 is a deficient number, since it is larger than the sum of its proper divisors (78732897).

131221455 is an equidigital number, since it uses as much as digits as its factorization.

131221455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8748105.

The product of its digits is 1200, while the sum is 24.

The square root of 131221455 is about 11455.1933637106. The cubic root of 131221455 is about 508.1613337883.

Adding to 131221455 its reverse (554122131), we get a palindrome (685343586).

The spelling of 131221455 in words is "one hundred thirty-one million, two hundred twenty-one thousand, four hundred fifty-five".