21820876 has 72 divisors (see below), whose sum is σ = 50274000. Its totient is φ = 8184960.

The previous prime is 21820871. The next prime is 21820879. The reversal of 21820876 is 67802812.

It is not an unprimeable number, because it can be changed into a prime (21820871) 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, 62350 + ... + 62698.

It is an arithmetic number, because the mean of its divisors is an integer number (698250).

Almost surely, 2^21820876 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 21820876, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25137000).

21820876 is an abundant number, since it is smaller than the sum of its proper divisors (28453124).

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

21820876 is a wasteful number, since it uses less digits than its factorization.

21820876 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 21820876 is about 4671.2820510006. The cubic root of 21820876 is about 279.4413862794.

The spelling of 21820876 in words is "twenty-one million, eight hundred twenty thousand, eight hundred seventy-six".