61643120517775 has 12 divisors (see below), whose sum is σ = 76439009980872. Its totient is φ = 49313502518240.

The previous prime is 61643120517773. The next prime is 61643120517917. The reversal of 61643120517775 is 57771502134616.

It is a happy number.

It is not a de Polignac number, because 61643120517775 - 2¹ = 61643120517773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61643120517773) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23580892 + ... + 26064241.

It is an arithmetic number, because the mean of its divisors is an integer number (6369917498406).

Almost surely, 2^{61643120517775} is an apocalyptic number.

61643120517775 is a deficient number, since it is larger than the sum of its proper divisors (14795889463097).

61643120517775 is a wasteful number, since it uses less digits than its factorization.

61643120517775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49694810 (or 49694805 counting only the distinct ones).

The product of its (nonzero) digits is 7408800, while the sum is 55.

The spelling of 61643120517775 in words is "sixty-one trillion, six hundred forty-three billion, one hundred twenty million, five hundred seventeen thousand, seven hundred seventy-five".