131020204001221 has 8 divisors (see below), whose sum is σ = 131341221710360. Its totient is φ = 130699189585152.

The previous prime is 131020204001213. The next prime is 131020204001279. The reversal of 131020204001221 is 122100402020131.

It can be written as a sum of positive squares in 4 ways, for example, as 117407756856196 + 13612447145025 = 10835486^2 + 3689505^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 131020204001221 - 2³ = 131020204001213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131020204007221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91516321 + ... + 92936953.

It is an arithmetic number, because the mean of its divisors is an integer number (16417652713795).

Almost surely, 2^{131020204001221} is an apocalyptic number.

It is an amenable number.

131020204001221 is a deficient number, since it is larger than the sum of its proper divisors (321017709139).

131020204001221 is a wasteful number, since it uses less digits than its factorization.

131020204001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1646535.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 131020204001221 its reverse (122100402020131), we get a palindrome (253120606021352).

The spelling of 131020204001221 in words is "one hundred thirty-one trillion, twenty billion, two hundred four million, one thousand, two hundred twenty-one".