128926381 has 4 divisors (see below), whose sum is σ = 135712000. Its totient is φ = 122140764.

The previous prime is 128926327. The next prime is 128926403. The reversal of 128926381 is 183629821.

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, and also an emirpimes, since its reverse is a distinct semiprime: 183629821 = 73 ⋅2515477.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128926381 is a prime.

It is a super-2 number, since 2×128926381² = 33244023435514322, 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 (128926321) 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, 3392781 + ... + 3392818.

It is an arithmetic number, because the mean of its divisors is an integer number (33928000).

Almost surely, 2^128926381 is an apocalyptic number.

It is an amenable number.

128926381 is a deficient number, since it is larger than the sum of its proper divisors (6785619).

128926381 is an equidigital number, since it uses as much as digits as its factorization.

128926381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6785618.

The product of its digits is 41472, while the sum is 40.

The square root of 128926381 is about 11354.5753333183. The cubic root of 128926381 is about 505.1812975170.

The spelling of 128926381 in words is "one hundred twenty-eight million, nine hundred twenty-six thousand, three hundred eighty-one".