64036640 has 96 divisors (see below), whose sum is σ = 161164080. Its totient is φ = 23998464.

The previous prime is 64036627. The next prime is 64036649. The reversal of 64036640 is 4663046.

It can be written as a sum of positive squares in 8 ways, for example, as 43930384 + 20106256 = 6628^2 + 4484^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (64036649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171494 + ... + 171866.

Almost surely, 2^64036640 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 64036640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80582040).

64036640 is an abundant number, since it is smaller than the sum of its proper divisors (97127440).

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

64036640 is a wasteful number, since it uses less digits than its factorization.

64036640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454 (or 446 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 29.

The square root of 64036640 is about 8002.2896723375. The cubic root of 64036640 is about 400.0763187710.

Adding to 64036640 its reverse (4663046), we get a palindrome (68699686).

The spelling of 64036640 in words is "sixty-four million, thirty-six thousand, six hundred forty".