1988641 has 4 divisors (see below), whose sum is σ = 1995952. Its totient is φ = 1981332.

The previous prime is 1988633. The next prime is 1988653. The reversal of 1988641 is 1468891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1468891 = 47 ⋅31253.

It is a cyclic number.

It is not a de Polignac number, because 1988641 - 2³ = 1988633 is a prime.

It is an Ulam number.

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 1988641.

It is not an unprimeable number, because it can be changed into a prime (1988611) 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, 3231 + ... + 3796.

It is an arithmetic number, because the mean of its divisors is an integer number (498988).

2^1988641 is an apocalyptic number.

It is an amenable number.

1988641 is a deficient number, since it is larger than the sum of its proper divisors (7311).

1988641 is an equidigital number, since it uses as much as digits as its factorization.

1988641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7310.

The product of its digits is 13824, while the sum is 37.

The square root of 1988641 is about 1410.1918309223. The cubic root of 1988641 is about 125.7531279400.

The spelling of 1988641 in words is "one million, nine hundred eighty-eight thousand, six hundred forty-one".