131721139 has 8 divisors (see below), whose sum is σ = 148331520. Its totient is φ = 115883400.

The previous prime is 131721137. The next prime is 131721197. The reversal of 131721139 is 931127131.

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

It is a cyclic number.

It is not a de Polignac number, because 131721139 - 2¹ = 131721137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131721131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 192799 + ... + 193480.

It is an arithmetic number, because the mean of its divisors is an integer number (18541440).

Almost surely, 2^131721139 is an apocalyptic number.

131721139 is a deficient number, since it is larger than the sum of its proper divisors (16610381).

131721139 is a wasteful number, since it uses less digits than its factorization.

131721139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386321.

The product of its digits is 1134, while the sum is 28.

The square root of 131721139 is about 11476.9830094847. The cubic root of 131721139 is about 508.8055334824.

The spelling of 131721139 in words is "one hundred thirty-one million, seven hundred twenty-one thousand, one hundred thirty-nine".