128364431 has 4 divisors (see below), whose sum is σ = 138238632. Its totient is φ = 118490232.

The previous prime is 128364419. The next prime is 128364461. The reversal of 128364431 is 134463821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128364431 - 2¹⁸ = 128102287 is a prime.

It is a super-2 number, since 2×128364431² = 32954854291907522, 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 (128364461) 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, 4937081 + ... + 4937106.

It is an arithmetic number, because the mean of its divisors is an integer number (34559658).

Almost surely, 2^128364431 is an apocalyptic number.

128364431 is a deficient number, since it is larger than the sum of its proper divisors (9874201).

128364431 is an equidigital number, since it uses as much as digits as its factorization.

128364431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9874200.

The product of its digits is 13824, while the sum is 32.

The square root of 128364431 is about 11329.8027785130. The cubic root of 128364431 is about 504.4462524795.

The spelling of 128364431 in words is "one hundred twenty-eight million, three hundred sixty-four thousand, four hundred thirty-one".