3896161821 has 6 divisors (see below), whose sum is σ = 5627789310. Its totient is φ = 2597441208.

The previous prime is 3896161781. The next prime is 3896161859. The reversal of 3896161821 is 1281616983.

3896161821 is a `hidden beast` number, since 3 + 8 + 9 + 6 + 1 + 618 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2784672900 + 1111488921 = 52770^2 + 33339^2 .

It is not a de Polignac number, because 3896161821 - 2⁷ = 3896161693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3896161921) 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 5 ways as a sum of consecutive naturals, for example, 216453426 + ... + 216453443.

It is an arithmetic number, because the mean of its divisors is an integer number (937964885).

Almost surely, 2^3896161821 is an apocalyptic number.

It is an amenable number.

3896161821 is a deficient number, since it is larger than the sum of its proper divisors (1731627489).

3896161821 is a wasteful number, since it uses less digits than its factorization.

3896161821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432906875 (or 432906872 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 3896161821 is about 62419.2423936722. The cubic root of 3896161821 is about 1573.5443772674.

The spelling of 3896161821 in words is "three billion, eight hundred ninety-six million, one hundred sixty-one thousand, eight hundred twenty-one".