1271661 has 4 divisors (see below), whose sum is σ = 1695552. Its totient is φ = 847772.

The previous prime is 1271659. The next prime is 1271671. The reversal of 1271661 is 1661721.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1271661 - 2¹ = 1271659 is a prime.

It is a super-3 number, since 3×1271661³ = 6169291790314733343, which contains 333 as substring.

It is a D-number.

It is a Curzon number.

1271661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271671) 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 in 3 ways as a sum of consecutive naturals, for example, 211941 + ... + 211946.

It is an arithmetic number, because the mean of its divisors is an integer number (423888).

2^1271661 is an apocalyptic number.

It is an amenable number.

1271661 is a deficient number, since it is larger than the sum of its proper divisors (423891).

1271661 is an equidigital number, since it uses as much as digits as its factorization.

1271661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423890.

The product of its digits is 504, while the sum is 24.

The square root of 1271661 is about 1127.6794757377. The cubic root of 1271661 is about 108.3404040092.

The spelling of 1271661 in words is "one million, two hundred seventy-one thousand, six hundred sixty-one".