819752781604 has 9 divisors (see below), whose sum is σ = 1434570536721. Its totient is φ = 409875485400.

The previous prime is 819752781593. The next prime is 819752781619. The reversal of 819752781604 is 406187257918.

The square root of 819752781604 is 905402.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 623787199204 + 195965582400 = 789802^2 + 442680^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1584454 + ... + 2037154.

Almost surely, 2^819752781604 is an apocalyptic number.

819752781604 is the 905402-nd square number.

It is an amenable number.

819752781604 is a deficient number, since it is larger than the sum of its proper divisors (614817755117).

819752781604 is an frugal number, since it uses more digits than its factorization.

819752781604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905406 (or 452703 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 58.

The spelling of 819752781604 in words is "eight hundred nineteen billion, seven hundred fifty-two million, seven hundred eighty-one thousand, six hundred four".