381940128 has 144 divisors (see below), whose sum is σ = 1152103680. Its totient is φ = 119688192.

The previous prime is 381940127. The next prime is 381940129. The reversal of 381940128 is 821049183.

It is an interprime number because it is at equal distance from previous prime (381940127) and next prime (381940129).

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×381940128² = 291756522753312768, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 381940092 and 381940101.

It is not an unprimeable number, because it can be changed into a prime (381940123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1220100 + ... + 1220412.

It is an arithmetic number, because the mean of its divisors is an integer number (8000720).

Almost surely, 2^381940128 is an apocalyptic number.

381940128 is a gapful number since it is divisible by the number (38) 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 381940128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (576051840).

381940128 is an abundant number, since it is smaller than the sum of its proper divisors (770163552).

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

381940128 is a wasteful number, since it uses less digits than its factorization.

381940128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571 (or 560 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 381940128 is about 19543.2885666666. The cubic root of 381940128 is about 725.5462410540.

The spelling of 381940128 in words is "three hundred eighty-one million, nine hundred forty thousand, one hundred twenty-eight".