105421021 has 4 divisors (see below), whose sum is σ = 105661600. Its totient is φ = 105180444.

The previous prime is 105421009. The next prime is 105421027. The reversal of 105421021 is 120124501.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 105421021 - 2⁵ = 105420989 is a prime.

It is a super-2 number, since 2×105421021² = 22227183337364882, 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 = 105420986 and 105421004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105421027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119631 + ... + 120508.

It is an arithmetic number, because the mean of its divisors is an integer number (26415400).

Almost surely, 2^105421021 is an apocalyptic number.

It is an amenable number.

105421021 is a deficient number, since it is larger than the sum of its proper divisors (240579).

105421021 is an equidigital number, since it uses as much as digits as its factorization.

105421021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240578.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 105421021 is about 10267.4739347125. The cubic root of 105421021 is about 472.3991121162.

Adding to 105421021 its reverse (120124501), we get a palindrome (225545522).

The spelling of 105421021 in words is "one hundred five million, four hundred twenty-one thousand, twenty-one".