1997872128 has 528 divisors, whose sum is σ = 7248410624. Its totient is φ = 537477120.

The previous prime is 1997872111. The next prime is 1997872133. The reversal of 1997872128 is 8212787991.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 53996526 + ... + 53996562.

Almost surely, 2^1997872128 is an apocalyptic number.

1997872128 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 1997872128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3624205312).

1997872128 is an abundant number, since it is smaller than the sum of its proper divisors (5250538496).

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

1997872128 is an equidigital number, since it uses as much as digits as its factorization.

1997872128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 80 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 54.

The square root of 1997872128 is about 44697.5628865825. The cubic root of 1997872128 is about 1259.4740662160.

The spelling of 1997872128 in words is "one billion, nine hundred ninety-seven million, eight hundred seventy-two thousand, one hundred twenty-eight".