20821626 has 48 divisors (see below), whose sum is σ = 51839424. Its totient is φ = 5916672.

The previous prime is 20821609. The next prime is 20821627. The reversal of 20821626 is 62612802.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20821626.

It is not an unprimeable number, because it can be changed into a prime (20821627) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32061 + ... + 32703.

It is an arithmetic number, because the mean of its divisors is an integer number (1079988).

Almost surely, 2^20821626 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20821626, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25919712).

20821626 is an abundant number, since it is smaller than the sum of its proper divisors (31017798).

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

20821626 is a wasteful number, since it uses less digits than its factorization.

20821626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 915 (or 912 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20821626 is about 4563.0719915425. The cubic root of 20821626 is about 275.1090520662.

The spelling of 20821626 in words is "twenty million, eight hundred twenty-one thousand, six hundred twenty-six".