1997988 has 24 divisors (see below), whose sum is σ = 4694592. Its totient is φ = 661344.

The previous prime is 1997969. The next prime is 1997999. The reversal of 1997988 is 8897991.

1997988 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 1997988.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1506 + ... + 2502.

It is an arithmetic number, because the mean of its divisors is an integer number (195608).

2^1997988 is an apocalyptic number.

It is an amenable number.

1997988 is an abundant number, since it is smaller than the sum of its proper divisors (2696604).

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

1997988 is a wasteful number, since it uses less digits than its factorization.

1997988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1171 (or 1169 counting only the distinct ones).

The product of its digits is 326592, while the sum is 51.

The square root of 1997988 is about 1413.5020339568. The cubic root of 1997988 is about 125.9498414614.

The spelling of 1997988 in words is "one million, nine hundred ninety-seven thousand, nine hundred eighty-eight".