640636562 has 16 divisors (see below), whose sum is σ = 986391000. Its totient is φ = 311871360.

The previous prime is 640636561. The next prime is 640636567. The reversal of 640636562 is 265636046.

640636562 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 441798361 + 198838201 = 21019^2 + 14101^2 .

It is not an unprimeable number, because it can be changed into a prime (640636561) 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, 34064 + ... + 49412.

Almost surely, 2^640636562 is an apocalyptic number.

640636562 is a deficient number, since it is larger than the sum of its proper divisors (345754438).

640636562 is a wasteful number, since it uses less digits than its factorization.

640636562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15901.

The product of its (nonzero) digits is 155520, while the sum is 38.

The square root of 640636562 is about 25310.7993157071. The cubic root of 640636562 is about 862.0594961832.

The spelling of 640636562 in words is "six hundred forty million, six hundred thirty-six thousand, five hundred sixty-two".