64820721548 has 24 divisors (see below), whose sum is σ = 123764397120. Its totient is φ = 29460215120.

The previous prime is 64820721547. The next prime is 64820721551. The reversal of 64820721548 is 84512702846.

It is not an unprimeable number, because it can be changed into a prime (64820721547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 272015 + ... + 451257.

It is an arithmetic number, because the mean of its divisors is an integer number (5156849880).

Almost surely, 2^64820721548 is an apocalyptic number.

It is an amenable number.

64820721548 is a deficient number, since it is larger than the sum of its proper divisors (58943675572).

64820721548 is a wasteful number, since it uses less digits than its factorization.

64820721548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187477 (or 187475 counting only the distinct ones).

The product of its (nonzero) digits is 860160, while the sum is 47.

The spelling of 64820721548 in words is "sixty-four billion, eight hundred twenty million, seven hundred twenty-one thousand, five hundred forty-eight".