1997928 has 24 divisors (see below), whose sum is σ = 5411250. Its totient is φ = 665952.

The previous prime is 1997921. The next prime is 1997939. The reversal of 1997928 is 8297991.

It can be written as a sum of positive squares in only one way, i.e., 1855044 + 142884 = 1362^2 + 378^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (1997921) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13803 + ... + 13946.

2^1997928 is an apocalyptic number.

1997928 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1997928 is an abundant number, since it is smaller than the sum of its proper divisors (3413322).

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

1997928 is a wasteful number, since it uses less digits than its factorization.

1997928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27761 (or 27754 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 1997928 is about 1413.4808099157. The cubic root of 1997928 is about 125.9485806820.

The spelling of 1997928 in words is "one million, nine hundred ninety-seven thousand, nine hundred twenty-eight".