131211220221 has 32 divisors (see below), whose sum is σ = 196055959680. Its totient is φ = 86724747648.

The previous prime is 131211220213. The next prime is 131211220229. The reversal of 131211220221 is 122022112131.

131211220221 is a `hidden beast` number, since 1 + 312 + 112 + 20 + 221 = 666.

It is an interprime number because it is at equal distance from previous prime (131211220213) and next prime (131211220229).

It is not a de Polignac number, because 131211220221 - 2³ = 131211220213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 131211220194 and 131211220203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131211220229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2925850 + ... + 2970356.

It is an arithmetic number, because the mean of its divisors is an integer number (6126748740).

Almost surely, 2^131211220221 is an apocalyptic number.

It is an amenable number.

131211220221 is a deficient number, since it is larger than the sum of its proper divisors (64844739459).

131211220221 is a wasteful number, since it uses less digits than its factorization.

131211220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45450 (or 45444 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 131211220221 its reverse (122022112131), we get a palindrome (253233332352).

The spelling of 131211220221 in words is "one hundred thirty-one billion, two hundred eleven million, two hundred twenty thousand, two hundred twenty-one".