105621431 has 4 divisors (see below), whose sum is σ = 105642864. Its totient is φ = 105600000.

The previous prime is 105621409. The next prime is 105621443. The reversal of 105621431 is 134126501.

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 105621431 - 2²² = 101427127 is a prime.

It is a super-2 number, since 2×105621431² = 22311773372975522, 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 = 105621397 and 105621406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105621491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 806 + ... + 14556.

It is an arithmetic number, because the mean of its divisors is an integer number (26410716).

Almost surely, 2^105621431 is an apocalyptic number.

105621431 is a deficient number, since it is larger than the sum of its proper divisors (21433).

105621431 is an equidigital number, since it uses as much as digits as its factorization.

105621431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21432.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 105621431 is about 10277.2287607117. The cubic root of 105621431 is about 472.6982731235.

Adding to 105621431 its reverse (134126501), we get a palindrome (239747932).

The spelling of 105621431 in words is "one hundred five million, six hundred twenty-one thousand, four hundred thirty-one".