105781639 has 4 divisors (see below), whose sum is σ = 106224480. Its totient is φ = 105338800.

The previous prime is 105781619. The next prime is 105781657. The reversal of 105781639 is 936187501.

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 105781639 - 2¹¹ = 105779591 is a prime.

It is a super-2 number, since 2×105781639² = 22379510299052642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105781609) 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, 221062 + ... + 221539.

It is an arithmetic number, because the mean of its divisors is an integer number (26556120).

Almost surely, 2^105781639 is an apocalyptic number.

105781639 is a deficient number, since it is larger than the sum of its proper divisors (442841).

105781639 is an equidigital number, since it uses as much as digits as its factorization.

105781639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442840.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 105781639 is about 10285.0201263780. The cubic root of 105781639 is about 472.9371507421.

The spelling of 105781639 in words is "one hundred five million, seven hundred eighty-one thousand, six hundred thirty-nine".