640298181251 has 8 divisors (see below), whose sum is σ = 664217937600. Its totient is φ = 616773792960.

The previous prime is 640298181223. The next prime is 640298181311. The reversal of 640298181251 is 152181892046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640298181251 - 2²⁶ = 640231072387 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640298181196 and 640298181205.

It is not an unprimeable number, because it can be changed into a prime (640298181851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98838716 + ... + 98845193.

It is an arithmetic number, because the mean of its divisors is an integer number (83027242200).

Almost surely, 2^640298181251 is an apocalyptic number.

640298181251 is a deficient number, since it is larger than the sum of its proper divisors (23919756349).

640298181251 is a wasteful number, since it uses less digits than its factorization.

640298181251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197684029.

The product of its (nonzero) digits is 276480, while the sum is 47.

The spelling of 640298181251 in words is "six hundred forty billion, two hundred ninety-eight million, one hundred eighty-one thousand, two hundred fifty-one".