22021871 has 4 divisors (see below), whose sum is σ = 22437432. Its totient is φ = 21606312.

The previous prime is 22021861. The next prime is 22021877. The reversal of 22021871 is 17812022.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 22021871 - 2⁶ = 22021807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22021877) 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, 207701 + ... + 207806.

It is an arithmetic number, because the mean of its divisors is an integer number (5609358).

Almost surely, 2^22021871 is an apocalyptic number.

22021871 is a deficient number, since it is larger than the sum of its proper divisors (415561).

22021871 is an equidigital number, since it uses as much as digits as its factorization.

22021871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415560.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 22021871 is about 4692.7466370986. The cubic root of 22021871 is about 280.2967559525.

Adding to 22021871 its reverse (17812022), we get a palindrome (39833893).

The spelling of 22021871 in words is "twenty-two million, twenty-one thousand, eight hundred seventy-one".