1997641 has 8 divisors (see below), whose sum is σ = 2148480. Its totient is φ = 1851408.

The previous prime is 1997617. The next prime is 1997647. The reversal of 1997641 is 1467991.

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 1997641 - 2⁹ = 1997129 is a prime.

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 1997641.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997647) 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 7 ways as a sum of consecutive naturals, for example, 226 + ... + 2011.

It is an arithmetic number, because the mean of its divisors is an integer number (268560).

2^1997641 is an apocalyptic number.

It is an amenable number.

1997641 is a deficient number, since it is larger than the sum of its proper divisors (150839).

1997641 is a wasteful number, since it uses less digits than its factorization.

1997641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2303.

The product of its digits is 13608, while the sum is 37.

The square root of 1997641 is about 1413.3792838442. The cubic root of 1997641 is about 125.9425496049.

The spelling of 1997641 in words is "one million, nine hundred ninety-seven thousand, six hundred forty-one".