1988397 has 6 divisors (see below), whose sum is σ = 2872142. Its totient is φ = 1325592.

The previous prime is 1988353. The next prime is 1988411. The reversal of 1988397 is 7938891.

It can be written as a sum of positive squares in only one way, i.e., 1602756 + 385641 = 1266^2 + 621^2 .

It is not a de Polignac number, because 1988397 - 2¹⁰ = 1987373 is a prime.

It is a Duffinian number.

1988397 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988347) 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 5 ways as a sum of consecutive naturals, for example, 110458 + ... + 110475.

2^1988397 is an apocalyptic number.

It is an amenable number.

1988397 is a deficient number, since it is larger than the sum of its proper divisors (883745).

1988397 is a wasteful number, since it uses less digits than its factorization.

1988397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220939 (or 220936 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 1988397 is about 1410.1053152159. The cubic root of 1988397 is about 125.7479845585.

The spelling of 1988397 in words is "one million, nine hundred eighty-eight thousand, three hundred ninety-seven".