3991550400 has 420 divisors, whose sum is σ = 15453669880. Its totient is φ = 1007769600.

The previous prime is 3991550399. The next prime is 3991550441. The reversal of 3991550400 is 40551993.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 59 ways as a sum of consecutive naturals, for example, 2461590 + ... + 2463210.

Almost surely, 2^3991550400 is an apocalyptic number.

3991550400 is a gapful number since it is divisible by the number (30) 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 3991550400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7726834940).

3991550400 is an abundant number, since it is smaller than the sum of its proper divisors (11462119480).

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

3991550400 is a wasteful number, since it uses less digits than its factorization.

3991550400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1674 (or 1650 counting only the distinct ones).

The product of its (nonzero) digits is 24300, while the sum is 36.

The square root of 3991550400 is about 63178.7179357100. The cubic root of 3991550400 is about 1586.2825220098.

The spelling of 3991550400 in words is "three billion, nine hundred ninety-one million, five hundred fifty thousand, four hundred".