128001605 has 4 divisors (see below), whose sum is σ = 153601932. Its totient is φ = 102401280.

The previous prime is 128001553. The next prime is 128001637. The reversal of 128001605 is 506100821.

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

It can be written as a sum of positive squares in 2 ways, for example, as 27019204 + 100982401 = 5198^2 + 10049^2 .

It is not a de Polignac number, because 128001605 - 2²² = 123807301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12800156 + ... + 12800165.

It is an arithmetic number, because the mean of its divisors is an integer number (38400483).

Almost surely, 2^128001605 is an apocalyptic number.

It is an amenable number.

128001605 is a deficient number, since it is larger than the sum of its proper divisors (25600327).

128001605 is an equidigital number, since it uses as much as digits as its factorization.

128001605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25600326.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 128001605 is about 11313.7794304114. The cubic root of 128001605 is about 503.9705263797.

The spelling of 128001605 in words is "one hundred twenty-eight million, one thousand, six hundred five".