1851898 has 4 divisors (see below), whose sum is σ = 2777850. Its totient is φ = 925948.

The previous prime is 1851877. The next prime is 1851901. The reversal of 1851898 is 8981581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8981581 = 7 ⋅1283083.

It can be written as a sum of positive squares in only one way, i.e., 1151329 + 700569 = 1073^2 + 837^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 1851898.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 462973 + ... + 462976.

2^1851898 is an apocalyptic number.

1851898 is a deficient number, since it is larger than the sum of its proper divisors (925952).

1851898 is an equidigital number, since it uses as much as digits as its factorization.

1851898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925951.

The product of its digits is 23040, while the sum is 40.

The square root of 1851898 is about 1360.8445906862. The cubic root of 1851898 is about 122.8020700136.

The spelling of 1851898 in words is "one million, eight hundred fifty-one thousand, eight hundred ninety-eight".