131321021 has 4 divisors (see below), whose sum is σ = 141422652. Its totient is φ = 121219392.

The previous prime is 131321017. The next prime is 131321083. The reversal of 131321021 is 120123131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120123131 = 439 ⋅273629.

It can be written as a sum of positive squares in 2 ways, for example, as 86229796 + 45091225 = 9286^2 + 6715^2 .

It is a cyclic number.

It is not a de Polignac number, because 131321021 - 2² = 131321017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 131320987 and 131321005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131321221) 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, 5050796 + ... + 5050821.

It is an arithmetic number, because the mean of its divisors is an integer number (35355663).

Almost surely, 2^131321021 is an apocalyptic number.

It is an amenable number.

131321021 is a deficient number, since it is larger than the sum of its proper divisors (10101631).

131321021 is a wasteful number, since it uses less digits than its factorization.

131321021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10101630.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 131321021 is about 11459.5384287501. The cubic root of 131321021 is about 508.2898259876.

Adding to 131321021 its reverse (120123131), we get a palindrome (251444152).

The spelling of 131321021 in words is "one hundred thirty-one million, three hundred twenty-one thousand, twenty-one".