61691347779345 has 24 divisors (see below), whose sum is σ = 106955114626152. Its totient is φ = 32894838259200.

The previous prime is 61691347779331. The next prime is 61691347779353. The reversal of 61691347779345 is 54397774319616.

61691347779345 is a `hidden beast` number, since 6 + 1 + 6 + 91 + 347 + 77 + 93 + 45 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 984935168721 + 60706412610624 = 992439^2 + 7791432^2 .

It is not a de Polignac number, because 61691347779345 - 2²⁷ = 61691213561617 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 150081846 + ... + 150492335.

It is an arithmetic number, because the mean of its divisors is an integer number (4456463109423).

Almost surely, 2^{61691347779345} is an apocalyptic number.

It is an amenable number.

61691347779345 is a deficient number, since it is larger than the sum of its proper divisors (45263766846807).

61691347779345 is a wasteful number, since it uses less digits than its factorization.

61691347779345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300578753 (or 300578750 counting only the distinct ones).

The product of its digits is 720135360, while the sum is 72.

The spelling of 61691347779345 in words is "sixty-one trillion, six hundred ninety-one billion, three hundred forty-seven million, seven hundred seventy-nine thousand, three hundred forty-five".