61580321280 has 640 divisors, whose sum is σ = 234827112960. Its totient is φ = 15431565312.

The previous prime is 61580321249. The next prime is 61580321293. The reversal of 61580321280 is 8212308516.

It is a happy number.

61580321280 is a `hidden beast` number, since 6 + 1 + 58 + 0 + 321 + 280 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 95177917 + ... + 95178563.

It is an arithmetic number, because the mean of its divisors is an integer number (366917364).

Almost surely, 2^61580321280 is an apocalyptic number.

61580321280 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 61580321280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117413556480).

61580321280 is an abundant number, since it is smaller than the sum of its proper divisors (173246791680).

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

61580321280 is an frugal number, since it uses more digits than its factorization.

61580321280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

Adding to 61580321280 its reverse (8212308516), we get a palindrome (69792629796).

The spelling of 61580321280 in words is "sixty-one billion, five hundred eighty million, three hundred twenty-one thousand, two hundred eighty".