3977915981 has 16 divisors (see below), whose sum is σ = 4619375040. Its totient is φ = 3393809280.

The previous prime is 3977915959. The next prime is 3977916013. The reversal of 3977915981 is 1895197793.

It is a cyclic number.

It is not a de Polignac number, because 3977915981 - 2¹⁰ = 3977914957 is a prime.

It is a super-2 number, since 2×3977915981² = 31647631103790384722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3977915981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3977915281) 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 15 ways as a sum of consecutive naturals, for example, 186275 + ... + 206528.

It is an arithmetic number, because the mean of its divisors is an integer number (288710940).

Almost surely, 2^3977915981 is an apocalyptic number.

It is an amenable number.

3977915981 is a deficient number, since it is larger than the sum of its proper divisors (641459059).

3977915981 is a wasteful number, since it uses less digits than its factorization.

3977915981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392876.

The product of its digits is 4286520, while the sum is 59.

The square root of 3977915981 is about 63070.7220586541. The cubic root of 3977915981 is about 1584.4743095727.

The spelling of 3977915981 in words is "three billion, nine hundred seventy-seven million, nine hundred fifteen thousand, nine hundred eighty-one".