661570271 has 2 divisors, whose sum is σ = 661570272. Its totient is φ = 661570270.

The previous prime is 661570207. The next prime is 661570277. The reversal of 661570271 is 172075166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661570271 - 2⁶ = 661570207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661570277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330785135 + 330785136.

It is an arithmetic number, because the mean of its divisors is an integer number (330785136).

Almost surely, 2^661570271 is an apocalyptic number.

661570271 is a deficient number, since it is larger than the sum of its proper divisors (1).

661570271 is an equidigital number, since it uses as much as digits as its factorization.

661570271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 661570271 is about 25721.0083589271. The cubic root of 661570271 is about 871.3487122439.

The spelling of 661570271 in words is "six hundred sixty-one million, five hundred seventy thousand, two hundred seventy-one".