21840876 has 36 divisors (see below), whose sum is σ = 56255472. Its totient is φ = 7142304.

The previous prime is 21840851. The next prime is 21840877. The reversal of 21840876 is 67804812.

It is a tau number, because it is divible by the number of its divisors (36).

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 21840876.

It is not an unprimeable number, because it can be changed into a prime (21840877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3816 + ... + 7631.

It is an arithmetic number, because the mean of its divisors is an integer number (1562652).

Almost surely, 2^21840876 is an apocalyptic number.

21840876 is the 3816-th pentagonal number.

It is an amenable number.

21840876 is an abundant number, since it is smaller than the sum of its proper divisors (34414596).

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

21840876 is a wasteful number, since it uses less digits than its factorization.

21840876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11510 (or 11505 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 21840876 is about 4673.4223006272. The cubic root of 21840876 is about 279.5267345350.

The spelling of 21840876 in words is "twenty-one million, eight hundred forty thousand, eight hundred seventy-six".