61811078123520 has 3744 divisors, whose sum is σ = 267436773826560. Its totient is φ = 13544423424000.

The previous prime is 61811078123497. The next prime is 61811078123527. The reversal of 61811078123520 is 2532187011816.

61811078123520 is a `hidden beast` number, since 6 + 1 + 8 + 1 + 107 + 8 + 12 + 3 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61811078123527) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 870578565085 + ... + 870578565155.

It is an arithmetic number, because the mean of its divisors is an integer number (71430762240).

Almost surely, 2^{61811078123520} is an apocalyptic number.

61811078123520 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 61811078123520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133718386913280).

61811078123520 is an abundant number, since it is smaller than the sum of its proper divisors (205625695703040).

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

61811078123520 is an equidigital number, since it uses as much as digits as its factorization.

61811078123520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 61811078123520 in words is "sixty-one trillion, eight hundred eleven billion, seventy-eight million, one hundred twenty-three thousand, five hundred twenty".