1861138 has 4 divisors (see below), whose sum is σ = 2791710. Its totient is φ = 930568.

The previous prime is 1861121. The next prime is 1861141. The reversal of 1861138 is 8311681.

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: 8311681 = 7 ⋅1187383.

It can be written as a sum of positive squares in only one way, i.e., 1682209 + 178929 = 1297^2 + 423^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 465283 + ... + 465286.

2^1861138 is an apocalyptic number.

1861138 is a deficient number, since it is larger than the sum of its proper divisors (930572).

1861138 is an equidigital number, since it uses as much as digits as its factorization.

1861138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930571.

The product of its digits is 1152, while the sum is 28.

The square root of 1861138 is about 1364.2353169450. The cubic root of 1861138 is about 123.0059705829.

The spelling of 1861138 in words is "one million, eight hundred sixty-one thousand, one hundred thirty-eight".