61651778642688 has 1152 divisors, whose sum is σ = 190826176020480. Its totient is φ = 17532875243520.

The previous prime is 61651778642669. The next prime is 61651778642737. The reversal of 61651778642688 is 88624687715616.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 167988497481 + ... + 167988497847.

It is an arithmetic number, because the mean of its divisors is an integer number (165647722240).

Almost surely, 2^{61651778642688} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61651778642688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95413088010240).

61651778642688 is an abundant number, since it is smaller than the sum of its proper divisors (129174397377792).

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

61651778642688 is a wasteful number, since it uses less digits than its factorization.

61651778642688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 705 (or 691 counting only the distinct ones).

The product of its digits is 1300561920, while the sum is 75.

The spelling of 61651778642688 in words is "sixty-one trillion, six hundred fifty-one billion, seven hundred seventy-eight million, six hundred forty-two thousand, six hundred eighty-eight".