20645628 has 96 divisors (see below), whose sum is σ = 55050240. Its totient is φ = 5987520.

The previous prime is 20645579. The next prime is 20645671. The reversal of 20645628 is 82654602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 162501 + ... + 162627.

It is an arithmetic number, because the mean of its divisors is an integer number (573440).

Almost surely, 2^20645628 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20645628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27525120).

20645628 is an abundant number, since it is smaller than the sum of its proper divisors (34404612).

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

20645628 is a wasteful number, since it uses less digits than its factorization.

20645628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 20645628 is about 4543.7460316351. The cubic root of 20645628 is about 274.3317238976.

The spelling of 20645628 in words is "twenty million, six hundred forty-five thousand, six hundred twenty-eight".