131987321 has 4 divisors (see below), whose sum is σ = 132068352. Its totient is φ = 131906292.

The previous prime is 131987299. The next prime is 131987333. The reversal of 131987321 is 123789131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 131987321 - 2⁶ = 131987257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131987341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38021 + ... + 41346.

It is an arithmetic number, because the mean of its divisors is an integer number (33017088).

Almost surely, 2^131987321 is an apocalyptic number.

It is an amenable number.

131987321 is a deficient number, since it is larger than the sum of its proper divisors (81031).

131987321 is an equidigital number, since it uses as much as digits as its factorization.

131987321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81030.

The product of its digits is 9072, while the sum is 35.

The square root of 131987321 is about 11488.5734971754. The cubic root of 131987321 is about 509.1480341848.

The spelling of 131987321 in words is "one hundred thirty-one million, nine hundred eighty-seven thousand, three hundred twenty-one".