3815161981 has 32 divisors (see below), whose sum is σ = 4349116800. Its totient is φ = 3325132800.

The previous prime is 3815161967. The next prime is 3815162003. The reversal of 3815161981 is 1891615183.

It is a cyclic number.

It is not a de Polignac number, because 3815161981 - 2⁷ = 3815161853 is a prime.

It is a super-2 number, since 2×3815161981² = 29110921882535688722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3815161901) 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 31 ways as a sum of consecutive naturals, for example, 2707005 + ... + 2708413.

It is an arithmetic number, because the mean of its divisors is an integer number (135909900).

Almost surely, 2^3815161981 is an apocalyptic number.

It is an amenable number.

3815161981 is a deficient number, since it is larger than the sum of its proper divisors (533954819).

3815161981 is a wasteful number, since it uses less digits than its factorization.

3815161981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1629.

The product of its digits is 51840, while the sum is 43.

The square root of 3815161981 is about 61766.9975067592. The cubic root of 3815161981 is about 1562.5634465629.

The spelling of 3815161981 in words is "three billion, eight hundred fifteen million, one hundred sixty-one thousand, nine hundred eighty-one".