640060636 has 6 divisors (see below), whose sum is σ = 1120106120. Its totient is φ = 320030316.

The previous prime is 640060601. The next prime is 640060637. The reversal of 640060636 is 636060046.

It is a junction number, because it is equal to n+sod(n) for n = 640060598 and 640060607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640060637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80007576 + ... + 80007583.

Almost surely, 2^640060636 is an apocalyptic number.

It is an amenable number.

640060636 is a deficient number, since it is larger than the sum of its proper divisors (480045484).

640060636 is a wasteful number, since it uses less digits than its factorization.

640060636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160015163 (or 160015161 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 31.

The square root of 640060636 is about 25299.4196771388. The cubic root of 640060636 is about 861.8010910495.

The spelling of 640060636 in words is "six hundred forty million, sixty thousand, six hundred thirty-six".