64720000 has 80 divisors (see below), whose sum is σ = 161315550. Its totient is φ = 25856000.

The previous prime is 64719983. The next prime is 64720001. The reversal of 64720000 is 2746.

It can be written as a sum of positive squares in 5 ways, for example, as 6594624 + 58125376 = 2568^2 + 7624^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 64720000.

It is not an unprimeable number, because it can be changed into a prime (64720001) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 79596 + ... + 80404.

Almost surely, 2^64720000 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 64720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80657775).

64720000 is an abundant number, since it is smaller than the sum of its proper divisors (96595550).

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

64720000 is an frugal number, since it uses more digits than its factorization.

64720000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843 (or 816 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 64720000 is about 8044.8741444475. The cubic root of 64720000 is about 401.4944098947.

Adding to 64720000 its reverse (2746), we get a palindrome (64722746).

The spelling of 64720000 in words is "sixty-four million, seven hundred twenty thousand".