819125987 has 4 divisors (see below), whose sum is σ = 831351816. Its totient is φ = 806900160.

The previous prime is 819125947. The next prime is 819126001. The reversal of 819125987 is 789521918.

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 819125987 - 2¹⁰ = 819124963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (819125947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6112814 + ... + 6112947.

It is an arithmetic number, because the mean of its divisors is an integer number (207837954).

Almost surely, 2^819125987 is an apocalyptic number.

819125987 is a deficient number, since it is larger than the sum of its proper divisors (12225829).

819125987 is a wasteful number, since it uses less digits than its factorization.

819125987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12225828.

The product of its digits is 362880, while the sum is 50.

The square root of 819125987 is about 28620.3771288919. The cubic root of 819125987 is about 935.6574963007.

The spelling of 819125987 in words is "eight hundred nineteen million, one hundred twenty-five thousand, nine hundred eighty-seven".