20821632 has 128 divisors (see below), whose sum is σ = 61575360. Its totient is φ = 6193152.

The previous prime is 20821627. The next prime is 20821637. The reversal of 20821632 is 23612802.

It is an interprime number because it is at equal distance from previous prime (20821627) and next prime (20821637).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (20821637) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 214608 + ... + 214704.

Almost surely, 2^20821632 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 20821632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30787680).

20821632 is an abundant number, since it is smaller than the sum of its proper divisors (40753728).

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

20821632 is a wasteful number, since it uses less digits than its factorization.

20821632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 20821632 is about 4563.0726489943. The cubic root of 20821632 is about 275.1090784915.

The spelling of 20821632 in words is "twenty million, eight hundred twenty-one thousand, six hundred thirty-two".