640308481 has 8 divisors (see below), whose sum is σ = 654835104. Its totient is φ = 625928160.

The previous prime is 640308467. The next prime is 640308497. The reversal of 640308481 is 184803046.

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 640308481 - 2⁷ = 640308353 is a prime.

It is a super-2 number, since 2×640308481² = 819989901681054722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640305481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27700 + ... + 45253.

It is an arithmetic number, because the mean of its divisors is an integer number (81854388).

Almost surely, 2^640308481 is an apocalyptic number.

It is an amenable number.

640308481 is a deficient number, since it is larger than the sum of its proper divisors (14526623).

640308481 is a wasteful number, since it uses less digits than its factorization.

640308481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73151.

The product of its (nonzero) digits is 18432, while the sum is 34.

The square root of 640308481 is about 25304.3174379393. The cubic root of 640308481 is about 861.9123125578.

The spelling of 640308481 in words is "six hundred forty million, three hundred eight thousand, four hundred eighty-one".