3978691115 has 16 divisors (see below), whose sum is σ = 5457860352. Its totient is φ = 2727560544.

The previous prime is 3978691099. The next prime is 3978691153. The reversal of 3978691115 is 5111968793.

It is a cyclic number.

It is not a de Polignac number, because 3978691115 - 2⁴ = 3978691099 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155672 + ... + 179418.

It is an arithmetic number, because the mean of its divisors is an integer number (341116272).

Almost surely, 2^3978691115 is an apocalyptic number.

3978691115 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

3978691115 is a deficient number, since it is larger than the sum of its proper divisors (1479169237).

3978691115 is a wasteful number, since it uses less digits than its factorization.

3978691115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28546.

The product of its digits is 408240, while the sum is 50.

The square root of 3978691115 is about 63076.8667183144. The cubic root of 3978691115 is about 1584.5772194171.

The spelling of 3978691115 in words is "three billion, nine hundred seventy-eight million, six hundred ninety-one thousand, one hundred fifteen".