3865121361 has 32 divisors (see below), whose sum is σ = 5789520000. Its totient is φ = 2548304064.

The previous prime is 3865121357. The next prime is 3865121371. The reversal of 3865121361 is 1631215683.

3865121361 is a `hidden beast` number, since 3 + 8 + 6 + 512 + 136 + 1 = 666.

It is not a de Polignac number, because 3865121361 - 2² = 3865121357 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3865121321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2274090 + ... + 2275788.

It is an arithmetic number, because the mean of its divisors is an integer number (180922500).

Almost surely, 2^3865121361 is an apocalyptic number.

It is an amenable number.

3865121361 is a deficient number, since it is larger than the sum of its proper divisors (1924398639).

3865121361 is a wasteful number, since it uses less digits than its factorization.

3865121361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2590 (or 2584 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 3865121361 is about 62170.1002170658. The cubic root of 3865121361 is about 1569.3544563656.

The spelling of 3865121361 in words is "three billion, eight hundred sixty-five million, one hundred twenty-one thousand, three hundred sixty-one".