105881021 has 4 divisors (see below), whose sum is σ = 106046844. Its totient is φ = 105715200.

The previous prime is 105881011. The next prime is 105881023. The reversal of 105881021 is 120188501.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120188501 = 23 ⋅5225587.

It can be written as a sum of positive squares in 2 ways, for example, as 99780121 + 6100900 = 9989^2 + 2470^2 .

It is a cyclic number.

It is not a de Polignac number, because 105881021 - 2²⁶ = 38772157 is a prime.

It is a super-2 number, since 2×105881021² = 22421581216004882, 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 (105881023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81950 + ... + 83231.

It is an arithmetic number, because the mean of its divisors is an integer number (26511711).

Almost surely, 2^105881021 is an apocalyptic number.

It is an amenable number.

105881021 is a deficient number, since it is larger than the sum of its proper divisors (165823).

105881021 is an equidigital number, since it uses as much as digits as its factorization.

105881021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165822.

The product of its (nonzero) digits is 640, while the sum is 26.

The square root of 105881021 is about 10289.8503876393. The cubic root of 105881021 is about 473.0852127585.

The spelling of 105881021 in words is "one hundred five million, eight hundred eighty-one thousand, twenty-one".