640635463 has 8 divisors (see below), whose sum is σ = 730498608. Its totient is φ = 556569984.

The previous prime is 640635421. The next prime is 640635467. The reversal of 640635463 is 364536046.

640635463 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640635463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640635467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1449181 + ... + 1449622.

It is an arithmetic number, because the mean of its divisors is an integer number (91312326).

Almost surely, 2^640635463 is an apocalyptic number.

640635463 is a deficient number, since it is larger than the sum of its proper divisors (89863145).

640635463 is a wasteful number, since it uses less digits than its factorization.

640635463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2898833.

The product of its (nonzero) digits is 155520, while the sum is 37.

The square root of 640635463 is about 25310.7776055972. Note that the first 3 decimals coincide. The cubic root of 640635463 is about 862.0590032340.

The spelling of 640635463 in words is "six hundred forty million, six hundred thirty-five thousand, four hundred sixty-three".