20821376 has 32 divisors (see below), whose sum is σ = 42374880. Its totient is φ = 10186240.

The previous prime is 20821373. The next prime is 20821387. The reversal of 20821376 is 67312802.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20821373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4286 + ... + 7746.

It is an arithmetic number, because the mean of its divisors is an integer number (1324215).

Almost surely, 2^20821376 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 20821376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21187440).

20821376 is an abundant number, since it is smaller than the sum of its proper divisors (21553504).

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

20821376 is an equidigital number, since it uses as much as digits as its factorization.

20821376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3522 (or 3510 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 20821376 is about 4563.0445976343. The cubic root of 20821376 is about 275.1079510068.

The spelling of 20821376 in words is "twenty million, eight hundred twenty-one thousand, three hundred seventy-six".