61331337648 has 720 divisors, whose sum is σ = 227148274080. Its totient is φ = 15899369472.

The previous prime is 61331337643. The next prime is 61331337659. The reversal of 61331337648 is 84673313316.

It is a happy number.

61331337648 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (61331337643) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 93922090 + ... + 93922742.

It is an arithmetic number, because the mean of its divisors is an integer number (315483714).

Almost surely, 2^61331337648 is an apocalyptic number.

61331337648 is a gapful number since it is divisible by the number (68) 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 61331337648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113574137040).

61331337648 is an abundant number, since it is smaller than the sum of its proper divisors (165816936432).

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

61331337648 is a wasteful number, since it uses less digits than its factorization.

61331337648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736 (or 711 counting only the distinct ones).

The product of its digits is 653184, while the sum is 45.

The spelling of 61331337648 in words is "sixty-one billion, three hundred thirty-one million, three hundred thirty-seven thousand, six hundred forty-eight".