128013381 has 6 divisors (see below), whose sum is σ = 184908230. Its totient is φ = 85342248.

The previous prime is 128013371. The next prime is 128013397. The reversal of 128013381 is 183310821.

128013381 is a `hidden beast` number, since 1 + 280 + 1 + 3 + 381 = 666.

It can be written as a sum of positive squares in only one way, i.e., 93896100 + 34117281 = 9690^2 + 5841^2 .

It is not a de Polignac number, because 128013381 - 2⁹ = 128012869 is a prime.

It is a super-2 number, since 2×128013381² = 32774851430102322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128013341) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7111846 + ... + 7111863.

Almost surely, 2^128013381 is an apocalyptic number.

It is an amenable number.

128013381 is a deficient number, since it is larger than the sum of its proper divisors (56894849).

128013381 is a wasteful number, since it uses less digits than its factorization.

128013381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14223715 (or 14223712 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 128013381 is about 11314.2998457704. The cubic root of 128013381 is about 503.9859808081.

The spelling of 128013381 in words is "one hundred twenty-eight million, thirteen thousand, three hundred eighty-one".