20829636 has 60 divisors (see below), whose sum is σ = 55525932. Its totient is φ = 6806592.

The previous prime is 20829581. The next prime is 20829637. The reversal of 20829636 is 63692802.

It can be written as a sum of positive squares in 2 ways, for example, as 6812100 + 14017536 = 2610^2 + 3744^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20829636.

It is not an unprimeable number, because it can be changed into a prime (20829637) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 16566 + ... + 17778.

Almost surely, 2^20829636 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 20829636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27762966).

20829636 is an abundant number, since it is smaller than the sum of its proper divisors (34696296).

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

20829636 is a wasteful number, since it uses less digits than its factorization.

20829636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1282 (or 1271 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 20829636 is about 4563.9496053309. The cubic root of 20829636 is about 275.1443253439.

The spelling of 20829636 in words is "twenty million, eight hundred twenty-nine thousand, six hundred thirty-six".