131721237 has 6 divisors (see below), whose sum is σ = 190264022. Its totient is φ = 87814152.

The previous prime is 131721223. The next prime is 131721283. The reversal of 131721237 is 732127131.

It can be written as a sum of positive squares in only one way, i.e., 120692196 + 11029041 = 10986^2 + 3321^2 .

It is not a de Polignac number, because 131721237 - 2¹⁰ = 131720213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 131721237.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131721137) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7317838 + ... + 7317855.

Almost surely, 2^131721237 is an apocalyptic number.

It is an amenable number.

131721237 is a deficient number, since it is larger than the sum of its proper divisors (58542785).

131721237 is a wasteful number, since it uses less digits than its factorization.

131721237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14635699 (or 14635696 counting only the distinct ones).

The product of its digits is 1764, while the sum is 27.

The square root of 131721237 is about 11476.9872788986. The cubic root of 131721237 is about 508.8056596654.

Adding to 131721237 its reverse (732127131), we get a palindrome (863848368).

The spelling of 131721237 in words is "one hundred thirty-one million, seven hundred twenty-one thousand, two hundred thirty-seven".