1317681 has 16 divisors (see below), whose sum is σ = 2006400. Its totient is φ = 854064.

The previous prime is 1317677. The next prime is 1317683. The reversal of 1317681 is 1867131.

It is not a de Polignac number, because 1317681 - 2² = 1317677 is a prime.

It is a super-2 number, since 2×1317681² = 3472566435522, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

1317681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1317683) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 340 + ... + 1658.

It is an arithmetic number, because the mean of its divisors is an integer number (125400).

2^1317681 is an apocalyptic number.

It is an amenable number.

1317681 is a deficient number, since it is larger than the sum of its proper divisors (688719).

1317681 is a wasteful number, since it uses less digits than its factorization.

1317681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1365 (or 1359 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 1317681 is about 1147.9028704555. The cubic root of 1317681 is about 109.6318546741.

It can be divided in two parts, 131768 and 1, that added together give a square (131769 = 363²).

The spelling of 1317681 in words is "one million, three hundred seventeen thousand, six hundred eighty-one".