1671256161 has 9 divisors (see below), whose sum is σ = 2414213841. Its totient is φ = 1114089012.

The previous prime is 1671256099. The next prime is 1671256163. The reversal of 1671256161 is 1616521761.

It is a happy number.

The square root of 1671256161 is 40881.

It is a perfect power (a square), and thus also a powerful number.

1671256161 is a `hidden beast` number, since 16 + 7 + 1 + 25 + 616 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 1671256161 - 2²³ = 1662867553 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1671256163) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 115830 + ... + 129456.

Almost surely, 2^1671256161 is an apocalyptic number.

1671256161 is the 40881-st square number.

1671256161 is the 20441-st centered octagonal number.

It is an amenable number.

1671256161 is a deficient number, since it is larger than the sum of its proper divisors (742957680).

1671256161 is an frugal number, since it uses more digits than its factorization.

1671256161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27260 (or 13630 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The cubic root of 1671256161 is about 1186.7183935268.

Multiplying 1671256161 by its sum of digits (36), we get a square (60165221796 = 245286²).

The spelling of 1671256161 in words is "one billion, six hundred seventy-one million, two hundred fifty-six thousand, one hundred sixty-one".