128506901 has 4 divisors (see below), whose sum is σ = 129179904. Its totient is φ = 127833900.

The previous prime is 128506891. The next prime is 128506907. The reversal of 128506901 is 109605821.

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 128506901 - 2¹⁴ = 128490517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128506907) 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, 336215 + ... + 336596.

It is an arithmetic number, because the mean of its divisors is an integer number (32294976).

Almost surely, 2^128506901 is an apocalyptic number.

It is an amenable number.

128506901 is a deficient number, since it is larger than the sum of its proper divisors (673003).

128506901 is an equidigital number, since it uses as much as digits as its factorization.

128506901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673002.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 128506901 is about 11336.0884347292. The cubic root of 128506901 is about 504.6328095727.

The spelling of 128506901 in words is "one hundred twenty-eight million, five hundred six thousand, nine hundred one".