640340541500 has 384 divisors, whose sum is σ = 1624228429824. Its totient is φ = 218363040000.

The previous prime is 640340541479. The next prime is 640340541521. The reversal of 640340541500 is 5145043046.

It is an interprime number because it is at equal distance from previous prime (640340541479) and next prime (640340541521).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1224360239 + ... + 1224360761.

It is an arithmetic number, because the mean of its divisors is an integer number (4229761536).

Almost surely, 2^640340541500 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 640340541500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (812114214912).

640340541500 is an abundant number, since it is smaller than the sum of its proper divisors (983887888324).

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

640340541500 is a wasteful number, since it uses less digits than its factorization.

640340541500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794 (or 782 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 640340541500 its reverse (5145043046), we get a palindrome (645485584546).

The spelling of 640340541500 in words is "six hundred forty billion, three hundred forty million, five hundred forty-one thousand, five hundred".