3965511978 has 20 divisors (see below), whose sum is σ = 8885684610. Its totient is φ = 1321837272.

The previous prime is 3965511967. The next prime is 3965511989. The reversal of 3965511978 is 8791155693.

3965511978 is a `hidden beast` number, since 3 + 9 + 6 + 551 + 19 + 78 = 666.

It is an interprime number because it is at equal distance from previous prime (3965511967) and next prime (3965511989).

It can be written as a sum of positive squares in only one way, i.e., 3904625169 + 60886809 = 62487^2 + 7803^2 .

It is a super-2 number, since 2×3965511978² = 31450570495322944968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 9 ways as a sum of consecutive naturals, for example, 12239073 + ... + 12239396.

Almost surely, 2^3965511978 is an apocalyptic number.

3965511978 is an abundant number, since it is smaller than the sum of its proper divisors (4920172632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3965511978 is a wasteful number, since it uses less digits than its factorization.

3965511978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24478483 (or 24478474 counting only the distinct ones).

The product of its digits is 2041200, while the sum is 54.

The square root of 3965511978 is about 62972.3112010350. The cubic root of 3965511978 is about 1582.8256835134.

The spelling of 3965511978 in words is "three billion, nine hundred sixty-five million, five hundred eleven thousand, nine hundred seventy-eight".