1997291520 has 600 divisors, whose sum is σ = 8373672384. Its totient is φ = 445906944.

The previous prime is 1997291489. The next prime is 1997291531. The reversal of 1997291520 is 251927991.

1997291520 is a `hidden beast` number, since 19 + 97 + 29 + 1 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 46448619 + ... + 46448661.

Almost surely, 2^1997291520 is an apocalyptic number.

1997291520 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 1997291520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4186836192).

1997291520 is an abundant number, since it is smaller than the sum of its proper divisors (6376380864).

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

1997291520 is an frugal number, since it uses more digits than its factorization.

1997291520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 102060, while the sum is 45.

The square root of 1997291520 is about 44691.0675638880. The cubic root of 1997291520 is about 1259.3520478015.

The spelling of 1997291520 in words is "one billion, nine hundred ninety-seven million, two hundred ninety-one thousand, five hundred twenty".