61611641517720 has 256 divisors, whose sum is σ = 218567328998400. Its totient is φ = 13594358937600.

The previous prime is 61611641517719. The next prime is 61611641517743. The reversal of 61611641517720 is 2771514611616.

It is a super-3 number, since 3×61611641517720³ (a number of 42 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61611641517720.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 124012447 + ... + 124508273.

It is an arithmetic number, because the mean of its divisors is an integer number (853778628900).

Almost surely, 2^{61611641517720} is an apocalyptic number.

61611641517720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61611641517720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109283664499200).

61611641517720 is an abundant number, since it is smaller than the sum of its proper divisors (156955687480680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61611641517720 is a wasteful number, since it uses less digits than its factorization.

61611641517720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500978 (or 500974 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 48.

The spelling of 61611641517720 in words is "sixty-one trillion, six hundred eleven billion, six hundred forty-one million, five hundred seventeen thousand, seven hundred twenty".