105421391 has 4 divisors (see below), whose sum is σ = 106068312. Its totient is φ = 104774472.

The previous prime is 105421387. The next prime is 105421447. The reversal of 105421391 is 193124501.

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 105421391 - 2² = 105421387 is a prime.

It is a super-2 number, since 2×105421391² = 22227339360749762, 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 105421391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105421321) 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, 323216 + ... + 323541.

It is an arithmetic number, because the mean of its divisors is an integer number (26517078).

Almost surely, 2^105421391 is an apocalyptic number.

105421391 is a deficient number, since it is larger than the sum of its proper divisors (646921).

105421391 is an equidigital number, since it uses as much as digits as its factorization.

105421391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646920.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 105421391 is about 10267.4919527604. The cubic root of 105421391 is about 472.3996647810.

Adding to 105421391 its reverse (193124501), we get a palindrome (298545892).

The spelling of 105421391 in words is "one hundred five million, four hundred twenty-one thousand, three hundred ninety-one".