131023421 has 4 divisors (see below), whose sum is σ = 135541500. Its totient is φ = 126505344.

The previous prime is 131023381. The next prime is 131023423. The reversal of 131023421 is 124320131.

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 74563225 + 56460196 = 8635^2 + 7514^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131023421 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 131023421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131023423) 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, 2258996 + ... + 2259053.

It is an arithmetic number, because the mean of its divisors is an integer number (33885375).

Almost surely, 2^131023421 is an apocalyptic number.

It is an amenable number.

131023421 is a deficient number, since it is larger than the sum of its proper divisors (4518079).

131023421 is an equidigital number, since it uses as much as digits as its factorization.

131023421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4518078.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 131023421 is about 11446.5462476679. The cubic root of 131023421 is about 507.9055730519.

Adding to 131023421 its reverse (124320131), we get a palindrome (255343552).

The spelling of 131023421 in words is "one hundred thirty-one million, twenty-three thousand, four hundred twenty-one".