6420636 has 18 divisors (see below), whose sum is σ = 16230032. Its totient is φ = 2140200.

The previous prime is 6420599. The next prime is 6420683. The reversal of 6420636 is 6360246.

6420636 is a `hidden beast` number, since 6 + 4 + 20 + 636 = 666.

6420636 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 89140 + ... + 89211.

Almost surely, 2^6420636 is an apocalyptic number.

It is an amenable number.

6420636 is an abundant number, since it is smaller than the sum of its proper divisors (9809396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6420636 is a wasteful number, since it uses less digits than its factorization.

6420636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178361 (or 178356 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 6420636 is about 2533.8973933449. The cubic root of 6420636 is about 185.8628888935.

It can be divided in two parts, 6420 and 636, that added together give a square (7056 = 84²).

The spelling of 6420636 in words is "six million, four hundred twenty thousand, six hundred thirty-six".