640025403251 has 16 divisors (see below), whose sum is σ = 691747472640. Its totient is φ = 588662411040.

The previous prime is 640025403247. The next prime is 640025403289. The reversal of 640025403251 is 152304520046.

It is a cyclic number.

It is not a de Polignac number, because 640025403251 - 2² = 640025403247 is a prime.

It is a super-2 number, since 2×640025403251² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640025403211) 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, 4411496 + ... + 4554266.

It is an arithmetic number, because the mean of its divisors is an integer number (43234217040).

Almost surely, 2^640025403251 is an apocalyptic number.

640025403251 is a deficient number, since it is larger than the sum of its proper divisors (51722069389).

640025403251 is a wasteful number, since it uses less digits than its factorization.

640025403251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144026.

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

Adding to 640025403251 its reverse (152304520046), we get a palindrome (792329923297).

The spelling of 640025403251 in words is "six hundred forty billion, twenty-five million, four hundred three thousand, two hundred fifty-one".