131301721 has 4 divisors (see below), whose sum is σ = 134504244. Its totient is φ = 128099200.

The previous prime is 131301719. The next prime is 131301739. The reversal of 131301721 is 127103131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39237696 + 92064025 = 6264^2 + 9595^2 .

It is a cyclic number.

It is not a de Polignac number, because 131301721 - 2¹ = 131301719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131305721) 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, 1601200 + ... + 1601281.

It is an arithmetic number, because the mean of its divisors is an integer number (33626061).

Almost surely, 2^131301721 is an apocalyptic number.

It is an amenable number.

131301721 is a deficient number, since it is larger than the sum of its proper divisors (3202523).

131301721 is an equidigital number, since it uses as much as digits as its factorization.

131301721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3202522.

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 131301721 is about 11458.6963045540. The cubic root of 131301721 is about 508.2649239722.

Adding to 131301721 its reverse (127103131), we get a palindrome (258404852).

The spelling of 131301721 in words is "one hundred thirty-one million, three hundred one thousand, seven hundred twenty-one".