105430021 has 4 divisors (see below), whose sum is σ = 107158444. Its totient is φ = 103701600.

The previous prime is 105430019. The next prime is 105430027. The reversal of 105430021 is 120034501.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120034501 = 17 ⋅7060853.

It can be written as a sum of positive squares in 2 ways, for example, as 1185921 + 104244100 = 1089^2 + 10210^2 .

It is a cyclic number.

It is not a de Polignac number, because 105430021 - 2¹ = 105430019 is a prime.

It is a super-2 number, since 2×105430021² = 22230978656120882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 105429977 and 105430004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105430027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 864120 + ... + 864241.

It is an arithmetic number, because the mean of its divisors is an integer number (26789611).

Almost surely, 2^105430021 is an apocalyptic number.

It is an amenable number.

105430021 is a deficient number, since it is larger than the sum of its proper divisors (1728423).

105430021 is an equidigital number, since it uses as much as digits as its factorization.

105430021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1728422.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 105430021 is about 10267.9122025853. The cubic root of 105430021 is about 472.4125549476.

Adding to 105430021 its reverse (120034501), we get a palindrome (225464522).

The spelling of 105430021 in words is "one hundred five million, four hundred thirty thousand, twenty-one".