1271645 has 4 divisors (see below), whose sum is σ = 1525980. Its totient is φ = 1017312.

The previous prime is 1271609. The next prime is 1271657. The reversal of 1271645 is 5461721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 145924 + 1125721 = 382^2 + 1061^2 .

It is a cyclic number.

It is not a de Polignac number, because 1271645 - 2¹² = 1267549 is a prime.

It is a congruent number.

It is an unprimeable number.

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, 127160 + ... + 127169.

It is an arithmetic number, because the mean of its divisors is an integer number (381495).

2^1271645 is an apocalyptic number.

It is an amenable number.

1271645 is a deficient number, since it is larger than the sum of its proper divisors (254335).

1271645 is an equidigital number, since it uses as much as digits as its factorization.

1271645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254334.

The product of its digits is 1680, while the sum is 26.

The square root of 1271645 is about 1127.6723815009. The cubic root of 1271645 is about 108.3399496288.

The spelling of 1271645 in words is "one million, two hundred seventy-one thousand, six hundred forty-five".