131204221 has 2 divisors, whose sum is σ = 131204222. Its totient is φ = 131204220.

The previous prime is 131204219. The next prime is 131204251. The reversal of 131204221 is 122402131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65836996 + 65367225 = 8114^2 + 8085^2 .

It is a cyclic number.

It is not a de Polignac number, because 131204221 - 2¹ = 131204219 is a prime.

Together with 131204219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 131204195 and 131204204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131204251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65602110 + 65602111.

It is an arithmetic number, because the mean of its divisors is an integer number (65602111).

Almost surely, 2^131204221 is an apocalyptic number.

It is an amenable number.

131204221 is a deficient number, since it is larger than the sum of its proper divisors (1).

131204221 is an equidigital number, since it uses as much as digits as its factorization.

131204221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 131204221 is about 11454.4411037815. The cubic root of 131204221 is about 508.1390863191.

Adding to 131204221 its reverse (122402131), we get a palindrome (253606352).

The spelling of 131204221 in words is "one hundred thirty-one million, two hundred four thousand, two hundred twenty-one".