2600001605 has 4 divisors (see below), whose sum is σ = 3120001932. Its totient is φ = 2080001280.

The previous prime is 2600001571. The next prime is 2600001617. The reversal of 2600001605 is 5061000062.

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 1297008196 + 1302993409 = 36014^2 + 36097^2 .

It is not a de Polignac number, because 2600001605 - 2¹⁰ = 2600000581 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, 260000156 + ... + 260000165.

It is an arithmetic number, because the mean of its divisors is an integer number (780000483).

Almost surely, 2^2600001605 is an apocalyptic number.

It is an amenable number.

2600001605 is a deficient number, since it is larger than the sum of its proper divisors (520000327).

2600001605 is an equidigital number, since it uses as much as digits as its factorization.

2600001605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520000326.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 2600001605 is about 50990.2108742453. The cubic root of 2600001605 is about 1375.0691500209.

Adding to 2600001605 its reverse (5061000062), we get a palindrome (7661001667).

The spelling of 2600001605 in words is "two billion, six hundred million, one thousand, six hundred five".