61605205 has 4 divisors (see below), whose sum is σ = 73926252. Its totient is φ = 49284160.

The previous prime is 61605199. The next prime is 61605223. The reversal of 61605205 is 50250616.

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 19731364 + 41873841 = 4442^2 + 6471^2 .

It is not a de Polignac number, because 61605205 - 2¹⁵ = 61572437 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61605205.

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, 6160516 + ... + 6160525.

It is an arithmetic number, because the mean of its divisors is an integer number (18481563).

Almost surely, 2^61605205 is an apocalyptic number.

It is an amenable number.

61605205 is a deficient number, since it is larger than the sum of its proper divisors (12321047).

61605205 is a wasteful number, since it uses less digits than its factorization.

61605205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12321046.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 61605205 is about 7848.8983303391. The cubic root of 61605205 is about 394.9472877371.

The spelling of 61605205 in words is "sixty-one million, six hundred five thousand, two hundred five".