21022071 has 16 divisors (see below), whose sum is σ = 33139200. Its totient is φ = 11598048.

The previous prime is 21022063. The next prime is 21022091. The reversal of 21022071 is 17022012.

It is not a de Polignac number, because 21022071 - 2³ = 21022063 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21022071.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022021) 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, 16651 + ... + 17868.

It is an arithmetic number, because the mean of its divisors is an integer number (2071200).

Almost surely, 2^21022071 is an apocalyptic number.

21022071 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21022071 is a deficient number, since it is larger than the sum of its proper divisors (12117129).

21022071 is a wasteful number, since it uses less digits than its factorization.

21022071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34558.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 21022071 is about 4584.9832060761. The cubic root of 21022071 is about 275.9890381070.

Adding to 21022071 its reverse (17022012), we get a palindrome (38044083).

The spelling of 21022071 in words is "twenty-one million, twenty-two thousand, seventy-one".