819561249 has 12 divisors (see below), whose sum is σ = 1274873236. Its totient is φ = 504345312.

The previous prime is 819561221. The next prime is 819561289. The reversal of 819561249 is 942165918.

819561249 is a `hidden beast` number, since 81 + 9 + 561 + 2 + 4 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 550371600 + 269189649 = 23460^2 + 16407^2 .

It is not a de Polignac number, because 819561249 - 2¹¹ = 819559201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (819561289) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3502282 + ... + 3502515.

Almost surely, 2^819561249 is an apocalyptic number.

It is an amenable number.

819561249 is a deficient number, since it is larger than the sum of its proper divisors (455311987).

819561249 is a wasteful number, since it uses less digits than its factorization.

819561249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7004816 (or 7004813 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 819561249 is about 28627.9801767432. The cubic root of 819561249 is about 935.8231948810.

The spelling of 819561249 in words is "eight hundred nineteen million, five hundred sixty-one thousand, two hundred forty-nine".