22780821 has 16 divisors (see below), whose sum is σ = 34781184. Its totient is φ = 12992304.

The previous prime is 22780817. The next prime is 22780837. The reversal of 22780821 is 12808722.

It is a happy number.

22780821 is nontrivially palindromic in base 4.

It is not a de Polignac number, because 22780821 - 2² = 22780817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22780801) 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, 18016 + ... + 19238.

It is an arithmetic number, because the mean of its divisors is an integer number (2173824).

Almost surely, 2^22780821 is an apocalyptic number.

22780821 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

22780821 is a deficient number, since it is larger than the sum of its proper divisors (12000363).

22780821 is a wasteful number, since it uses less digits than its factorization.

22780821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2120.

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 22780821 is about 4772.9258322333. The cubic root of 22780821 is about 283.4804567711.

The spelling of 22780821 in words is "twenty-two million, seven hundred eighty thousand, eight hundred twenty-one".