3991551993 has 48 divisors (see below), whose sum is σ = 6999928320. Its totient is φ = 2233012320.

The previous prime is 3991551989. The next prime is 3991552031.

3991551993 is a `hidden beast` number, since 39 + 9 + 1 + 5 + 519 + 93 = 666.

3991551993 is nontrivially palindromic in base 10.

3991551993 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3991551993 - 2² = 3991551989 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (3991550993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4521 + ... + 89462.

It is an arithmetic number, because the mean of its divisors is an integer number (145831840).

Almost surely, 2^3991551993 is an apocalyptic number.

3991551993 is a gapful number since it is divisible by the number (33) formed by its first and last digit.

It is an amenable number.

3991551993 is a deficient number, since it is larger than the sum of its proper divisors (3008376327).

3991551993 is a wasteful number, since it uses less digits than its factorization.

3991551993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94027 (or 94010 counting only the distinct ones).

The product of its digits is 1476225, while the sum is 54.

The square root of 3991551993 is about 63178.7305428021. The cubic root of 3991551993 is about 1586.2827330346.

The spelling of 3991551993 in words is "three billion, nine hundred ninety-one million, five hundred fifty-one thousand, nine hundred ninety-three".