20641628 has 24 divisors (see below), whose sum is σ = 41903232. Its totient is φ = 8713584.

The previous prime is 20641627. The next prime is 20641631. The reversal of 20641628 is 82614602.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 20641628.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20641627) 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, 3626 + ... + 7377.

It is an arithmetic number, because the mean of its divisors is an integer number (1745968).

Almost surely, 2^20641628 is an apocalyptic number.

20641628 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20641628 is an abundant number, since it is smaller than the sum of its proper divisors (21261604).

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

20641628 is a wasteful number, since it uses less digits than its factorization.

20641628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11081 (or 11079 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 20641628 is about 4543.3058448667. The cubic root of 20641628 is about 274.3140058966.

The spelling of 20641628 in words is "twenty million, six hundred forty-one thousand, six hundred twenty-eight".