171221077 has 2 divisors, whose sum is σ = 171221078. Its totient is φ = 171221076.

The previous prime is 171221069. The next prime is 171221081. The reversal of 171221077 is 770122171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151560721 + 19660356 = 12311^2 + 4434^2 .

It is a cyclic number.

It is not a de Polignac number, because 171221077 - 2³ = 171221069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171221087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85610538 + 85610539.

It is an arithmetic number, because the mean of its divisors is an integer number (85610539).

Almost surely, 2^171221077 is an apocalyptic number.

It is an amenable number.

171221077 is a deficient number, since it is larger than the sum of its proper divisors (1).

171221077 is an equidigital number, since it uses as much as digits as its factorization.

171221077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1372, while the sum is 28.

The square root of 171221077 is about 13085.1471906127. The cubic root of 171221077 is about 555.2890056629.

The spelling of 171221077 in words is "one hundred seventy-one million, two hundred twenty-one thousand, seventy-seven".