1985631 has 4 divisors (see below), whose sum is σ = 2647512. Its totient is φ = 1323752.

The previous prime is 1985623. The next prime is 1985639. The reversal of 1985631 is 1365891.

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

It is an interprime number because it is at equal distance from previous prime (1985623) and next prime (1985639).

It is a cyclic number.

It is not a de Polignac number, because 1985631 - 2³ = 1985623 is a prime.

It is a super-2 number, since 2×1985631² = 7885460936322, which contains 22 as substring.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 1985592 and 1985601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1985639) by changing a digit.

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, 330936 + ... + 330941.

It is an arithmetic number, because the mean of its divisors is an integer number (661878).

2^1985631 is an apocalyptic number.

1985631 is a deficient number, since it is larger than the sum of its proper divisors (661881).

1985631 is an equidigital number, since it uses as much as digits as its factorization.

1985631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661880.

The product of its digits is 6480, while the sum is 33.

The square root of 1985631 is about 1409.1241960878. The cubic root of 1985631 is about 125.6896494054.

The spelling of 1985631 in words is "one million, nine hundred eighty-five thousand, six hundred thirty-one".