3991597056 has 260 divisors, whose sum is σ = 12202558632. Its totient is φ = 1299677184.

The previous prime is 3991597009. The next prime is 3991597061. The reversal of 3991597056 is 6507951993.

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

It is a junction number, because it is equal to n+sod(n) for n = 3991596993 and 3991597011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 17584015 + ... + 17584241.

Almost surely, 2^3991597056 is an apocalyptic number.

3991597056 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3991597056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6101279316).

3991597056 is an abundant number, since it is smaller than the sum of its proper divisors (8210961576).

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

3991597056 is an equidigital number, since it uses as much as digits as its factorization.

3991597056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 2296350, while the sum is 54.

The square root of 3991597056 is about 63179.0871728929. The cubic root of 3991597056 is about 1586.2887025079.

The spelling of 3991597056 in words is "three billion, nine hundred ninety-one million, five hundred ninety-seven thousand, fifty-six".