105381991 has 8 divisors (see below), whose sum is σ = 123805584. Its totient is φ = 88432320.

The previous prime is 105381979. The next prime is 105382009. The reversal of 105381991 is 199183501.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 105381991 - 2⁵ = 105381959 is a prime.

It is a super-2 number, since 2×105381991² = 22210728054248162, 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 105381991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105381901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 368326 + ... + 368611.

It is an arithmetic number, because the mean of its divisors is an integer number (15475698).

Almost surely, 2^105381991 is an apocalyptic number.

105381991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

105381991 is a deficient number, since it is larger than the sum of its proper divisors (18423593).

105381991 is a wasteful number, since it uses less digits than its factorization.

105381991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736961.

The product of its (nonzero) digits is 9720, while the sum is 37.

The square root of 105381991 is about 10265.5730965202. The cubic root of 105381991 is about 472.3408061824.

The spelling of 105381991 in words is "one hundred five million, three hundred eighty-one thousand, nine hundred ninety-one".