1997866 has 16 divisors (see below), whose sum is σ = 3304224. Its totient is φ = 900144.

The previous prime is 1997851. The next prime is 1997867. The reversal of 1997866 is 6687991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 225 + ... + 2011.

It is an arithmetic number, because the mean of its divisors is an integer number (206514).

2^1997866 is an apocalyptic number.

1997866 is a deficient number, since it is larger than the sum of its proper divisors (1306358).

1997866 is a wasteful number, since it uses less digits than its factorization.

1997866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1845.

The product of its digits is 163296, while the sum is 46.

The square root of 1997866 is about 1413.4588780718. The cubic root of 1997866 is about 125.9472778502.

Subtracting from 1997866 its product of digits (163296), we obtain a triangular number (1834570 = T₁₉₁₅).

The spelling of 1997866 in words is "one million, nine hundred ninety-seven thousand, eight hundred sixty-six".