621636 has 12 divisors (see below), whose sum is σ = 1450512. Its totient is φ = 207208.

The previous prime is 621631. The next prime is 621641. The reversal of 621636 is 636126.

It is an interprime number because it is at equal distance from previous prime (621631) and next prime (621641).

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 621636.

It is not an unprimeable number, because it can be changed into a prime (621631) by changing a digit.

621636 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25890 + ... + 25913.

It is an arithmetic number, because the mean of its divisors is an integer number (120876).

2⁶²¹⁶³⁶ is an apocalyptic number.

It is an amenable number.

621636 is an abundant number, since it is smaller than the sum of its proper divisors (828876).

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

621636 is a wasteful number, since it uses less digits than its factorization.

621636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51810 (or 51808 counting only the distinct ones).

The product of its digits is 1296, while the sum is 24.

The square root of 621636 is about 788.4389640296. The cubic root of 621636 is about 85.3451250524.

The spelling of 621636 in words is "six hundred twenty-one thousand, six hundred thirty-six".