1317661 has 4 divisors (see below), whose sum is σ = 1339324. Its totient is φ = 1296000.

The previous prime is 1317629. The next prime is 1317671. The reversal of 1317661 is 1667131.

It is a happy number.

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 562500 + 755161 = 750^2 + 869^2 .

It is a 4-Lehmer number, since φ(1317661) divides (1317661-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 1317661 - 2⁵ = 1317629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1317671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10740 + ... + 10861.

It is an arithmetic number, because the mean of its divisors is an integer number (334831).

2^1317661 is an apocalyptic number.

It is an amenable number.

1317661 is a deficient number, since it is larger than the sum of its proper divisors (21663).

1317661 is an equidigital number, since it uses as much as digits as its factorization.

1317661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21662.

The product of its digits is 756, while the sum is 25.

The square root of 1317661 is about 1147.8941588840. The cubic root of 1317661 is about 109.6313000006.

The spelling of 1317661 in words is "one million, three hundred seventeen thousand, six hundred sixty-one".