61800305605 has 4 divisors (see below), whose sum is σ = 74160366732. Its totient is φ = 49440244480.

The previous prime is 61800305549. The next prime is 61800305669. The reversal of 61800305605 is 50650300816.

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 48091174209 + 13709131396 = 219297^2 + 117086^2 .

It is not a de Polignac number, because 61800305605 - 2¹³ = 61800297413 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, 6180030556 + ... + 6180030565.

It is an arithmetic number, because the mean of its divisors is an integer number (18540091683).

Almost surely, 2^61800305605 is an apocalyptic number.

It is an amenable number.

61800305605 is a deficient number, since it is larger than the sum of its proper divisors (12360061127).

61800305605 is a wasteful number, since it uses less digits than its factorization.

61800305605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12360061126.

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 61800305605 in words is "sixty-one billion, eight hundred million, three hundred five thousand, six hundred five".