3991236480 has 384 divisors, whose sum is σ = 17184960000. Its totient is φ = 829255680.

The previous prime is 3991236449. The next prime is 3991236589. The reversal of 3991236480 is 846321993.

It is a happy number.

3991236480 is a `hidden beast` number, since 399 + 123 + 64 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 439021 + ... + 448019.

It is an arithmetic number, because the mean of its divisors is an integer number (44752500).

Almost surely, 2^3991236480 is an apocalyptic number.

3991236480 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 3991236480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8592480000).

3991236480 is an abundant number, since it is smaller than the sum of its proper divisors (13193723520).

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

3991236480 is a wasteful number, since it uses less digits than its factorization.

3991236480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9042 (or 9027 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 3991236480 is about 63176.2335059633. The cubic root of 3991236480 is about 1586.2409359247.

It can be divided in two parts, 3991 and 236480, that added together give a triangular number (240471 = T₆₉₃).

The spelling of 3991236480 in words is "three billion, nine hundred ninety-one million, two hundred thirty-six thousand, four hundred eighty".