1285198139 has 4 divisors (see below), whose sum is σ = 1286616024. Its totient is φ = 1283780256.

The previous prime is 1285198129. The next prime is 1285198141. The reversal of 1285198139 is 9318915821.

1285198139 = T₁₆₂ + T₁₆₃ + ... + T₁₉₇₅.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1285198139 - 2¹⁶ = 1285132603 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1285198093 and 1285198102.

It is not an unprimeable number, because it can be changed into a prime (1285198129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 707582 + ... + 709395.

It is an arithmetic number, because the mean of its divisors is an integer number (321654006).

Almost surely, 2^1285198139 is an apocalyptic number.

1285198139 is a deficient number, since it is larger than the sum of its proper divisors (1417885).

1285198139 is an equidigital number, since it uses as much as digits as its factorization.

1285198139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1417884.

The product of its digits is 155520, while the sum is 47.

The square root of 1285198139 is about 35849.6602354890. The cubic root of 1285198139 is about 1087.2348448366.

The spelling of 1285198139 in words is "one billion, two hundred eighty-five million, one hundred ninety-eight thousand, one hundred thirty-nine".