61511065505 has 4 divisors (see below), whose sum is σ = 73813278612. Its totient is φ = 49208852400.

The previous prime is 61511065493. The next prime is 61511065537. The reversal of 61511065505 is 50556011516.

61511065505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 24320714401 + 37190351104 = 155951^2 + 192848^2 .

It is a de Polignac number, because none of the positive numbers 2^k-61511065505 is a prime.

It is a super-2 number, since 2×61511065505² (a number of 22 digits) contains 22 as substring.

It is a Duffinian 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, 6151106546 + ... + 6151106555.

It is an arithmetic number, because the mean of its divisors is an integer number (18453319653).

Almost surely, 2^61511065505 is an apocalyptic number.

It is an amenable number.

61511065505 is a deficient number, since it is larger than the sum of its proper divisors (12302213107).

61511065505 is a wasteful number, since it uses less digits than its factorization.

61511065505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12302213106.

The product of its (nonzero) digits is 22500, while the sum is 35.

The spelling of 61511065505 in words is "sixty-one billion, five hundred eleven million, sixty-five thousand, five hundred five".