3999129120 has 648 divisors, whose sum is σ = 16861339404. Its totient is φ = 860461056.

The previous prime is 3999129103. The next prime is 3999129161. The reversal of 3999129120 is 219219993.

It can be written as a sum of positive squares in 2 ways, for example, as 3874315536 + 124813584 = 62244^2 + 11172^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 25472082 + ... + 25472238.

Almost surely, 2^3999129120 is an apocalyptic number.

3999129120 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 3999129120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8430669702).

3999129120 is an abundant number, since it is smaller than the sum of its proper divisors (12862210284).

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

3999129120 is a wasteful number, since it uses less digits than its factorization.

3999129120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 45.

The square root of 3999129120 is about 63238.6679176594. The cubic root of 3999129120 is about 1587.2858406208.

The spelling of 3999129120 in words is "three billion, nine hundred ninety-nine million, one hundred twenty-nine thousand, one hundred twenty".