1663631 has 4 divisors (see below), whose sum is σ = 1708632. Its totient is φ = 1618632.

The previous prime is 1663619. The next prime is 1663681. The reversal of 1663631 is 1363661.

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

It is a cyclic number.

It is not a de Polignac number, because 1663631 - 2¹⁸ = 1401487 is a prime.

It is a super-2 number, since 2×1663631² = 5535336208322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1663631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22445 + ... + 22518.

It is an arithmetic number, because the mean of its divisors is an integer number (427158).

2^1663631 is an apocalyptic number.

1663631 is a deficient number, since it is larger than the sum of its proper divisors (45001).

1663631 is an equidigital number, since it uses as much as digits as its factorization.

1663631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45000.

The product of its digits is 1944, while the sum is 26.

The square root of 1663631 is about 1289.8182042443. The cubic root of 1663631 is about 118.4910827855.

The spelling of 1663631 in words is "one million, six hundred sixty-three thousand, six hundred thirty-one".