1064721664 has 72 divisors (see below), whose sum is σ = 2190411720. Its totient is φ = 516292608.

The previous prime is 1064721659. The next prime is 1064721673. The reversal of 1064721664 is 4661274601.

It can be written as a sum of positive squares in 4 ways, for example, as 439321600 + 625400064 = 20960^2 + 25008^2 .

It is a super-2 number, since 2×1064721664² = 2267264443581857792, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1315692 + ... + 1316500.

It is an arithmetic number, because the mean of its divisors is an integer number (30422385).

Almost surely, 2^1064721664 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 1064721664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1095205860).

1064721664 is an abundant number, since it is smaller than the sum of its proper divisors (1125690056).

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

1064721664 is an frugal number, since it uses more digits than its factorization.

1064721664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975 (or 961 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 1064721664 is about 32630.0730002248. The cubic root of 1064721664 is about 1021.1245012171.

The spelling of 1064721664 in words is "one billion, sixty-four million, seven hundred twenty-one thousand, six hundred sixty-four".