61691347779344 has 20 divisors (see below), whose sum is σ = 119529494605980. Its totient is φ = 30845026590720.

The previous prime is 61691347779331. The next prime is 61691347779353. The reversal of 61691347779344 is 44397774319616.

It can be written as a sum of positive squares in 2 ways, for example, as 10880682793744 + 50810664985600 = 3298588^2 + 7128160^2 .

It is a super-2 number, since 2×61691347779344² (a number of 28 digits) contains 22 as substring.

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, 39669449 + ... + 41195240.

It is an arithmetic number, because the mean of its divisors is an integer number (5976474730299).

Almost surely, 2^{61691347779344} is an apocalyptic number.

It is an amenable number.

61691347779344 is a deficient number, since it is larger than the sum of its proper divisors (57838146826636).

61691347779344 is a wasteful number, since it uses less digits than its factorization.

61691347779344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80912378 (or 80912372 counting only the distinct ones).

The product of its digits is 576108288, while the sum is 71.

The spelling of 61691347779344 in words is "sixty-one trillion, six hundred ninety-one billion, three hundred forty-seven million, seven hundred seventy-nine thousand, three hundred forty-four".