2157005605 has 4 divisors (see below), whose sum is σ = 2588406732. Its totient is φ = 1725604480.

The previous prime is 2157005549. The next prime is 2157005629. The reversal of 2157005605 is 5065007512.

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 734735236 + 1422270369 = 27106^2 + 37713^2 .

It is not a de Polignac number, because 2157005605 - 2²³ = 2148616997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215700556 + ... + 215700565.

It is an arithmetic number, because the mean of its divisors is an integer number (647101683).

Almost surely, 2^2157005605 is an apocalyptic number.

It is an amenable number.

2157005605 is a deficient number, since it is larger than the sum of its proper divisors (431401127).

2157005605 is an equidigital number, since it uses as much as digits as its factorization.

2157005605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431401126.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 2157005605 is about 46443.5744210111. The cubic root of 2157005605 is about 1292.0632018097.

The spelling of 2157005605 in words is "two billion, one hundred fifty-seven million, five thousand, six hundred five".