640465345 has 8 divisors (see below), whose sum is σ = 827678376. Its totient is φ = 472958976.

The previous prime is 640465313. The next prime is 640465351. The reversal of 640465345 is 543564046.

It can be written as a sum of positive squares in 4 ways, for example, as 138391696 + 502073649 = 11764^2 + 22407^2 .

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 640465345 - 2⁵ = 640465313 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4926592 + ... + 4926721.

It is an arithmetic number, because the mean of its divisors is an integer number (103459797).

Almost surely, 2^640465345 is an apocalyptic number.

640465345 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

640465345 is a deficient number, since it is larger than the sum of its proper divisors (187213031).

640465345 is a wasteful number, since it uses less digits than its factorization.

640465345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9853331.

The product of its (nonzero) digits is 172800, while the sum is 37.

The square root of 640465345 is about 25307.4167982432. The cubic root of 640465345 is about 861.9826911216.

The spelling of 640465345 in words is "six hundred forty million, four hundred sixty-five thousand, three hundred forty-five".