131221547 has 2 divisors, whose sum is σ = 131221548. Its totient is φ = 131221546.

The previous prime is 131221537. The next prime is 131221583. The reversal of 131221547 is 745122131.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 131221547 - 2¹⁸ = 130959403 is a prime.

It is not a weakly prime, because it can be changed into another prime (131221507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65610773 + 65610774.

It is an arithmetic number, because the mean of its divisors is an integer number (65610774).

Almost surely, 2^131221547 is an apocalyptic number.

131221547 is a deficient number, since it is larger than the sum of its proper divisors (1).

131221547 is an equidigital number, since it uses as much as digits as its factorization.

131221547 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 26.

The square root of 131221547 is about 11455.1973793558. The cubic root of 131221547 is about 508.1614525464.

Adding to 131221547 its reverse (745122131), we get a palindrome (876343678).

The spelling of 131221547 in words is "one hundred thirty-one million, two hundred twenty-one thousand, five hundred forty-seven".