3966000991 has 4 divisors (see below), whose sum is σ = 3966187984. Its totient is φ = 3965814000.

The previous prime is 3966000931. The next prime is 3966001057. The reversal of 3966000991 is 1990006693.

It is a semiprime because it is the product of two primes.

It is a 4-Lehmer number, since φ(3966000991) divides (3966000991-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 3966000991 - 2¹¹ = 3965998943 is a prime.

It is a super-2 number, since 2×3966000991² = 31458327721225964162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3966000931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56910 + ... + 105691.

It is an arithmetic number, because the mean of its divisors is an integer number (991546996).

Almost surely, 2^3966000991 is an apocalyptic number.

3966000991 is a deficient number, since it is larger than the sum of its proper divisors (186993).

3966000991 is a wasteful number, since it uses less digits than its factorization.

3966000991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186992.

The product of its (nonzero) digits is 78732, while the sum is 43.

The square root of 3966000991 is about 62976.1938433882. The cubic root of 3966000991 is about 1582.8907436726.

The spelling of 3966000991 in words is "three billion, nine hundred sixty-six million, nine hundred ninety-one", and thus it is an aban number.