61458721408 has 64 divisors (see below), whose sum is σ = 140088611520. Its totient is φ = 26309283840.

The previous prime is 61458721367. The next prime is 61458721411. The reversal of 61458721408 is 80412785416.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 752328 + ... + 830008.

It is an arithmetic number, because the mean of its divisors is an integer number (2188884555).

Almost surely, 2^61458721408 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 61458721408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70044305760).

61458721408 is an abundant number, since it is smaller than the sum of its proper divisors (78629890112).

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

61458721408 is an equidigital number, since it uses as much as digits as its factorization.

61458721408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78585 (or 78573 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 46.

The spelling of 61458721408 in words is "sixty-one billion, four hundred fifty-eight million, seven hundred twenty-one thousand, four hundred eight".