640504351251 has 12 divisors (see below), whose sum is σ = 973866265320. Its totient is φ = 404529063840.

The previous prime is 640504351219. The next prime is 640504351271. The reversal of 640504351251 is 152153405046.

640504351251 is a `hidden beast` number, since 6 + 4 + 0 + 50 + 4 + 351 + 251 = 666.

It is not a de Polignac number, because 640504351251 - 2⁵ = 640504351219 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640504351271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1872819570 + ... + 1872819911.

It is an arithmetic number, because the mean of its divisors is an integer number (81155522110).

Almost surely, 2^640504351251 is an apocalyptic number.

640504351251 is a deficient number, since it is larger than the sum of its proper divisors (333361914069).

640504351251 is a wasteful number, since it uses less digits than its factorization.

640504351251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3745639506 (or 3745639503 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

Adding to 640504351251 its reverse (152153405046), we get a palindrome (792657756297).

The spelling of 640504351251 in words is "six hundred forty billion, five hundred four million, three hundred fifty-one thousand, two hundred fifty-one".