1866658 has 4 divisors (see below), whose sum is σ = 2799990. Its totient is φ = 933328.

The previous prime is 1866649. The next prime is 1866659. The reversal of 1866658 is 8566681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8566681 = 79 ⋅108439.

It can be written as a sum of positive squares in only one way, i.e., 1352569 + 514089 = 1163^2 + 717^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1866658.

It is not an unprimeable number, because it can be changed into a prime (1866659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 466663 + ... + 466666.

2^1866658 is an apocalyptic number.

1866658 is a deficient number, since it is larger than the sum of its proper divisors (933332).

1866658 is an equidigital number, since it uses as much as digits as its factorization.

1866658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 933331.

The product of its digits is 69120, while the sum is 40.

The square root of 1866658 is about 1366.2569304490. The cubic root of 1866658 is about 123.1274594749.

The spelling of 1866658 in words is "one million, eight hundred sixty-six thousand, six hundred fifty-eight".