64005640 has 16 divisors (see below), whose sum is σ = 144012780. Its totient is φ = 25602240.

The previous prime is 64005541. The next prime is 64005647. The reversal of 64005640 is 4650046.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 63968004 + 37636 = 7998^2 + 194^2 .

It is not an unprimeable number, because it can be changed into a prime (64005647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 800031 + ... + 800110.

Almost surely, 2^64005640 is an apocalyptic number.

It is an amenable number.

64005640 is an abundant number, since it is smaller than the sum of its proper divisors (80007140).

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

64005640 is a wasteful number, since it uses less digits than its factorization.

64005640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1600152 (or 1600148 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 64005640 is about 8000.3524922343. The cubic root of 64005640 is about 400.0117496549.

Adding to 64005640 its reverse (4650046), we get a palindrome (68655686).

The spelling of 64005640 in words is "sixty-four million, five thousand, six hundred forty".