640624011840 has 168 divisors, whose sum is σ = 2204729088120. Its totient is φ = 170736205824.

The previous prime is 640624011829. The next prime is 640624011869. The reversal of 640624011840 is 48110426046.

It is a happy number.

640624011840 is a `hidden beast` number, since 6 + 406 + 240 + 1 + 1 + 8 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 77079527424 + 563544484416 = 277632^2 + 750696^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 640624011795 and 640624011804.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5090152 + ... + 5214488.

Almost surely, 2^640624011840 is an apocalyptic number.

640624011840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640624011840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1102364544060).

640624011840 is an abundant number, since it is smaller than the sum of its proper divisors (1564105076280).

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

640624011840 is a wasteful number, since it uses less digits than its factorization.

640624011840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126149 (or 126136 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

Adding to 640624011840 its reverse (48110426046), we get a palindrome (688734437886).

The spelling of 640624011840 in words is "six hundred forty billion, six hundred twenty-four million, eleven thousand, eight hundred forty".