140905 has 4 divisors (see below), whose sum is σ = 169092. Its totient is φ = 112720.

The previous prime is 140897. The next prime is 140909. The reversal of 140905 is 509041.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 509041 = 13 ⋅39157.

It can be written as a sum of positive squares in 2 ways, for example, as 94249 + 46656 = 307^2 + 216^2 .

It is not a de Polignac number, because 140905 - 2³ = 140897 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (140909) 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, 14086 + ... + 14095.

It is an arithmetic number, because the mean of its divisors is an integer number (42273).

2¹⁴⁰⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

140905 is a deficient number, since it is larger than the sum of its proper divisors (28187).

140905 is an equidigital number, since it uses as much as digits as its factorization.

140905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28186.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 140905 is about 375.3731476811. The cubic root of 140905 is about 52.0365866780.

Adding to 140905 its reverse (509041), we get a palindrome (649946).

The spelling of 140905 in words is "one hundred forty thousand, nine hundred five".