640280481 has 4 divisors (see below), whose sum is σ = 853707312. Its totient is φ = 426853652.

The previous prime is 640280467. The next prime is 640280489. The reversal of 640280481 is 184082046.

640280481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640280481 - 2⁷ = 640280353 is a prime.

It is a super-2 number, since 2×640280481² = 819918188699182722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640280489) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106713411 + ... + 106713416.

It is an arithmetic number, because the mean of its divisors is an integer number (213426828).

Almost surely, 2^640280481 is an apocalyptic number.

It is an amenable number.

640280481 is a deficient number, since it is larger than the sum of its proper divisors (213426831).

640280481 is a wasteful number, since it uses less digits than its factorization.

640280481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213426830.

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 640280481 is about 25303.7641666215. The cubic root of 640280481 is about 861.8997488758.

The spelling of 640280481 in words is "six hundred forty million, two hundred eighty thousand, four hundred eighty-one".