2100605905 has 8 divisors (see below), whose sum is σ = 2520986472. Its totient is φ = 1680311808.

The previous prime is 2100605873. The next prime is 2100605957. The reversal of 2100605905 is 5095060012.

It can be written as a sum of positive squares in 4 ways, for example, as 170145936 + 1930459969 = 13044^2 + 43937^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2100605905 - 2⁵ = 2100605873 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59527 + ... + 88003.

It is an arithmetic number, because the mean of its divisors is an integer number (315123309).

Almost surely, 2^2100605905 is an apocalyptic number.

It is an amenable number.

2100605905 is a deficient number, since it is larger than the sum of its proper divisors (420380567).

2100605905 is a wasteful number, since it uses less digits than its factorization.

2100605905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43235.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 2100605905 is about 45832.3674383072. The cubic root of 2100605905 is about 1280.7023133538.

Adding to 2100605905 its reverse (5095060012), we get a palindrome (7195665917).

The spelling of 2100605905 in words is "two billion, one hundred million, six hundred five thousand, nine hundred five".