64138363280 has 80 divisors (see below), whose sum is σ = 150798567024. Its totient is φ = 25367347200.

The previous prime is 64138363279. The next prime is 64138363307. The reversal of 64138363280 is 8236383146.

It can be written as a sum of positive squares in 8 ways, for example, as 14205779344 + 49932583936 = 119188^2 + 223456^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×64138363280² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10092584 + ... + 10098936.

Almost surely, 2^64138363280 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 64138363280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75399283512).

64138363280 is an abundant number, since it is smaller than the sum of its proper divisors (86660203744).

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

64138363280 is a wasteful number, since it uses less digits than its factorization.

64138363280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7764 (or 7758 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 44.

The spelling of 64138363280 in words is "sixty-four billion, one hundred thirty-eight million, three hundred sixty-three thousand, two hundred eighty".