1997489664 has 240 divisors, whose sum is σ = 6256487952. Its totient is φ = 611057664.

The previous prime is 1997489639. The next prime is 1997489677. The reversal of 1997489664 is 4669847991.

1997489664 is a `hidden beast` number, since 1 + 9 + 97 + 489 + 6 + 64 = 666.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 3368152 + ... + 3368744.

Almost surely, 2^1997489664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1997489664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3128243976).

1997489664 is an abundant number, since it is smaller than the sum of its proper divisors (4258998288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1997489664 is a wasteful number, since it uses less digits than its factorization.

1997489664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 658 counting only the distinct ones).

The product of its digits is 23514624, while the sum is 63.

The square root of 1997489664 is about 44693.2843277377. The cubic root of 1997489664 is about 1259.3936916641.

The spelling of 1997489664 in words is "one billion, nine hundred ninety-seven million, four hundred eighty-nine thousand, six hundred sixty-four".