1997649 has 16 divisors (see below), whose sum is σ = 2981440. Its totient is φ = 1321920.

The previous prime is 1997647. The next prime is 1997657. The reversal of 1997649 is 9467991.

It is not a de Polignac number, because 1997649 - 2¹ = 1997647 is a prime.

It is a Duffinian 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 15 ways as a sum of consecutive naturals, for example, 6354 + ... + 6660.

It is an arithmetic number, because the mean of its divisors is an integer number (186340).

2^1997649 is an apocalyptic number.

It is an amenable number.

1997649 is a deficient number, since it is larger than the sum of its proper divisors (983791).

1997649 is a wasteful number, since it uses less digits than its factorization.

1997649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557 (or 551 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 1997649 is about 1413.3821139381. The cubic root of 1997649 is about 125.9427177264.

The spelling of 1997649 in words is "one million, nine hundred ninety-seven thousand, six hundred forty-nine".