1997297280 has 384 divisors, whose sum is σ = 7790515200. Its totient is φ = 467066880.

The previous prime is 1997297279. The next prime is 1997297287. The reversal of 1997297280 is 827927991.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1997297287) 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 47 ways as a sum of consecutive naturals, for example, 1836897 + ... + 1837983.

It is an arithmetic number, because the mean of its divisors is an integer number (20287800).

Almost surely, 2^1997297280 is an apocalyptic number.

1997297280 is a gapful number since it is divisible by the number (10) 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 1997297280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3895257600).

1997297280 is an abundant number, since it is smaller than the sum of its proper divisors (5793217920).

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

1997297280 is a wasteful number, since it uses less digits than its factorization.

1997297280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152 (or 1137 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 54.

The square root of 1997297280 is about 44691.1320062493. The cubic root of 1997297280 is about 1259.3532584178.

The spelling of 1997297280 in words is "one billion, nine hundred ninety-seven million, two hundred ninety-seven thousand, two hundred eighty".