61178947648 has 336 divisors, whose sum is σ = 157161701424. Its totient is φ = 23410114560.

The previous prime is 61178947637. The next prime is 61178947657. The reversal of 61178947648 is 84674987116.

It can be written as a sum of positive squares in 8 ways, for example, as 18548260864 + 42630686784 = 136192^2 + 206472^2 .

It is a Harshad number since it is a multiple of its sum of digits (61).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 181539736 + ... + 181540072.

It is an arithmetic number, because the mean of its divisors is an integer number (467743159).

Almost surely, 2^61178947648 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 61178947648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78580850712).

61178947648 is an abundant number, since it is smaller than the sum of its proper divisors (95982753776).

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

61178947648 is a wasteful number, since it uses less digits than its factorization.

61178947648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510 (or 493 counting only the distinct ones).

The product of its digits is 16257024, while the sum is 61.

The spelling of 61178947648 in words is "sixty-one billion, one hundred seventy-eight million, nine hundred forty-seven thousand, six hundred forty-eight".