21122105 has 8 divisors (see below), whose sum is σ = 25388232. Its totient is φ = 16869888.

The previous prime is 21122099. The next prime is 21122111. The reversal of 21122105 is 50122112.

It is an interprime number because it is at equal distance from previous prime (21122099) and next prime (21122111).

It can be written as a sum of positive squares in 4 ways, for example, as 5779216 + 15342889 = 2404^2 + 3917^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21122105 - 2¹⁰ = 21121081 is a prime.

It is a super-2 number, since 2×21122105² = 892286639262050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21122105.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 227 + ... + 6503.

It is an arithmetic number, because the mean of its divisors is an integer number (3173529).

Almost surely, 2^21122105 is an apocalyptic number.

It is an amenable number.

21122105 is a deficient number, since it is larger than the sum of its proper divisors (4266127).

21122105 is an equidigital number, since it uses as much as digits as its factorization.

21122105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6955.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 21122105 is about 4595.8791324403. The cubic root of 21122105 is about 276.4261122545.

Adding to 21122105 its reverse (50122112), we get a palindrome (71244217).

The spelling of 21122105 in words is "twenty-one million, one hundred twenty-two thousand, one hundred five".