1898774378 has 4 divisors (see below), whose sum is σ = 2848161570. Its totient is φ = 949387188.

The previous prime is 1898774377. The next prime is 1898774417. The reversal of 1898774378 is 8734778981.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1870822009 + 27952369 = 43253^2 + 5287^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1898774378.

It is not an unprimeable number, because it can be changed into a prime (1898774377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 474693593 + ... + 474693596.

Almost surely, 2^1898774378 is an apocalyptic number.

1898774378 is a deficient number, since it is larger than the sum of its proper divisors (949387192).

1898774378 is an equidigital number, since it uses as much as digits as its factorization.

1898774378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 949387191.

The product of its digits is 18966528, while the sum is 62.

The square root of 1898774378 is about 43574.9283189313. The cubic root of 1898774378 is about 1238.2959549352.

The spelling of 1898774378 in words is "one billion, eight hundred ninety-eight million, seven hundred seventy-four thousand, three hundred seventy-eight".