22201821 has 6 divisors (see below), whose sum is σ = 32069310. Its totient is φ = 14801208.

The previous prime is 22201819. The next prime is 22201867. The reversal of 22201821 is 12810222.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 14333796 + 7868025 = 3786^2 + 2805^2 .

It is not a de Polignac number, because 22201821 - 2¹ = 22201819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22201794 and 22201803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22201801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1233426 + ... + 1233443.

It is an arithmetic number, because the mean of its divisors is an integer number (5344885).

Almost surely, 2^22201821 is an apocalyptic number.

It is an amenable number.

22201821 is a deficient number, since it is larger than the sum of its proper divisors (9867489).

22201821 is a wasteful number, since it uses less digits than its factorization.

22201821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2466875 (or 2466872 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 22201821 is about 4711.8808346562. The cubic root of 22201821 is about 281.0581601393.

The spelling of 22201821 in words is "twenty-two million, two hundred one thousand, eight hundred twenty-one".