1997569728 has 224 divisors, whose sum is σ = 7322027520. Its totient is φ = 518814720.

The previous prime is 1997569697. The next prime is 1997569729. The reversal of 1997569728 is 8279657991.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (1997569729) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 125550 + ... + 140562.

Almost surely, 2^1997569728 is an apocalyptic number.

1997569728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1997569728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3661013760).

1997569728 is an abundant number, since it is smaller than the sum of its proper divisors (5324457792).

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

1997569728 is a wasteful number, since it uses less digits than its factorization.

1997569728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15052 (or 15036 counting only the distinct ones).

The product of its digits is 17146080, while the sum is 63.

The square root of 1997569728 is about 44694.1800238018. The cubic root of 1997569728 is about 1259.4105179088.

The spelling of 1997569728 in words is "one billion, nine hundred ninety-seven million, five hundred sixty-nine thousand, seven hundred twenty-eight".