128825381 has 4 divisors (see below), whose sum is σ = 128931264. Its totient is φ = 128719500.

The previous prime is 128825357. The next prime is 128825383. The reversal of 128825381 is 183528821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128825381 - 2⁶ = 128825317 is a prime.

It is a super-2 number, since 2×128825381² = 33191957579590322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128825383) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51095 + ... + 53556.

It is an arithmetic number, because the mean of its divisors is an integer number (32232816).

Almost surely, 2^128825381 is an apocalyptic number.

It is an amenable number.

128825381 is a deficient number, since it is larger than the sum of its proper divisors (105883).

128825381 is a wasteful number, since it uses less digits than its factorization.

128825381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105882.

The product of its digits is 30720, while the sum is 38.

The square root of 128825381 is about 11350.1269155900. The cubic root of 128825381 is about 505.0493445885.

The spelling of 128825381 in words is "one hundred twenty-eight million, eight hundred twenty-five thousand, three hundred eighty-one".