3878616661920 has 3456 divisors, whose sum is σ = 19605605160960. Its totient is φ = 710455173120.

The previous prime is 3878616661901. The next prime is 3878616661939. The reversal of 3878616661920 is 291666168783.

It is an interprime number because it is at equal distance from previous prime (3878616661901) and next prime (3878616661939).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 6265939371 + ... + 6265939989.

It is an arithmetic number, because the mean of its divisors is an integer number (5672918160).

Almost surely, 2^{3878616661920} is an apocalyptic number.

3878616661920 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 3878616661920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9802802580480).

3878616661920 is an abundant number, since it is smaller than the sum of its proper divisors (15726988499040).

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

3878616661920 is a wasteful number, since it uses less digits than its factorization.

3878616661920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 710 (or 683 counting only the distinct ones).

The product of its (nonzero) digits is 31352832, while the sum is 63.

The spelling of 3878616661920 in words is "three trillion, eight hundred seventy-eight billion, six hundred sixteen million, six hundred sixty-one thousand, nine hundred twenty".