1321663 has 8 divisors (see below), whose sum is σ = 1517600. Its totient is φ = 1127520.

The previous prime is 1321657. The next prime is 1321669. The reversal of 1321663 is 3661231.

It is an interprime number because it is at equal distance from previous prime (1321657) and next prime (1321669).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1321663 - 2¹⁷ = 1190591 is a prime.

1321663 is a lucky number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2173 + ... + 2713.

It is an arithmetic number, because the mean of its divisors is an integer number (189700).

2^1321663 is an apocalyptic number.

1321663 is a deficient number, since it is larger than the sum of its proper divisors (195937).

1321663 is an equidigital number, since it uses as much as digits as its factorization.

1321663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897.

The product of its digits is 648, while the sum is 22.

The square root of 1321663 is about 1149.6360293589. The cubic root of 1321663 is about 109.7421785513.

Adding to 1321663 its reverse (3661231), we get a palindrome (4982894).

The spelling of 1321663 in words is "one million, three hundred twenty-one thousand, six hundred sixty-three".