61506516605 has 4 divisors (see below), whose sum is σ = 73807819932. Its totient is φ = 49205213280.

The previous prime is 61506516587. The next prime is 61506516667. The reversal of 61506516605 is 50661560516.

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 13693446361 + 47813070244 = 117019^2 + 218662^2 .

It is not a de Polignac number, because 61506516605 - 2¹⁴ = 61506500221 is a prime.

It is a super-2 number, since 2×61506516605² (a number of 22 digits) contains 22 as substring.

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, 6150651656 + ... + 6150651665.

It is an arithmetic number, because the mean of its divisors is an integer number (18451954983).

Almost surely, 2^61506516605 is an apocalyptic number.

It is an amenable number.

61506516605 is a deficient number, since it is larger than the sum of its proper divisors (12301303327).

61506516605 is a wasteful number, since it uses less digits than its factorization.

61506516605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12301303326.

The product of its (nonzero) digits is 162000, while the sum is 41.

The spelling of 61506516605 in words is "sixty-one billion, five hundred six million, five hundred sixteen thousand, six hundred five".