132728221 has 2 divisors, whose sum is σ = 132728222. Its totient is φ = 132728220.

The previous prime is 132728201. The next prime is 132728227. The reversal of 132728221 is 122827231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 132572196 + 156025 = 11514^2 + 395^2 .

It is a cyclic number.

It is not a de Polignac number, because 132728221 - 2²³ = 124339613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 132728221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (132728227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66364110 + 66364111.

It is an arithmetic number, because the mean of its divisors is an integer number (66364111).

Almost surely, 2^132728221 is an apocalyptic number.

It is an amenable number.

132728221 is a deficient number, since it is larger than the sum of its proper divisors (1).

132728221 is an equidigital number, since it uses as much as digits as its factorization.

132728221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 28.

The square root of 132728221 is about 11520.7734549378. The cubic root of 132728221 is about 510.0989440221.

The spelling of 132728221 in words is "one hundred thirty-two million, seven hundred twenty-eight thousand, two hundred twenty-one".