3991277556 has 54 divisors (see below), whose sum is σ = 11736261810. Its totient is φ = 1140364512.

The previous prime is 3991277491. The next prime is 3991277557. The reversal of 3991277556 is 6557721993.

3991277556 is a `hidden beast` number, since 3 + 9 + 9 + 12 + 77 + 556 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3467325456 + 523952100 = 58884^2 + 22890^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991277557) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1129551 + ... + 1133078.

Almost surely, 2^3991277556 is an apocalyptic number.

3991277556 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

3991277556 is an abundant number, since it is smaller than the sum of its proper divisors (7744984254).

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

3991277556 is a wasteful number, since it uses less digits than its factorization.

3991277556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2262653 (or 2262641 counting only the distinct ones).

The product of its digits is 3572100, while the sum is 54.

The square root of 3991277556 is about 63176.5585957323. The cubic root of 3991277556 is about 1586.2463775307.

The spelling of 3991277556 in words is "three billion, nine hundred ninety-one million, two hundred seventy-seven thousand, five hundred fifty-six".