61946720640 has 768 divisors, whose sum is σ = 259164472320. Its totient is φ = 13328105472.

The previous prime is 61946720639. The next prime is 61946720657. The reversal of 61946720640 is 4602764916.

61946720640 is a `hidden beast` number, since 619 + 4 + 6 + 7 + 20 + 6 + 4 + 0 = 666.

61946720640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 62132622 + ... + 62133618.

It is an arithmetic number, because the mean of its divisors is an integer number (337453740).

Almost surely, 2^61946720640 is an apocalyptic number.

61946720640 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 61946720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129582236160).

61946720640 is an abundant number, since it is smaller than the sum of its proper divisors (197217751680).

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

61946720640 is a wasteful number, since it uses less digits than its factorization.

61946720640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1119 (or 1104 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 61946720640 in words is "sixty-one billion, nine hundred forty-six million, seven hundred twenty thousand, six hundred forty".