142805 has 10 divisors (see below), whose sum is σ = 185646. Its totient is φ = 105456.

The previous prime is 142799. The next prime is 142811. The reversal of 142805 is 508241.

It is an interprime number because it is at equal distance from previous prime (142799) and next prime (142811).

It can be written as a sum of positive squares in 5 ways, for example, as 128164 + 14641 = 358^2 + 121^2 .

It is not a de Polignac number, because 142805 - 2⁴ = 142789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 13.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 142805.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 10979 + ... + 10991.

142805 is a Friedman number, since it can be written as 5*(8+10/2)^4, using all its digits and the basic arithmetic operations.

2¹⁴²⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

142805 is a deficient number, since it is larger than the sum of its proper divisors (42841).

142805 is an frugal number, since it uses more digits than its factorization.

142805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 142805 is about 377.8954881975. The cubic root of 142805 is about 52.2694348617.

Multiplying 142805 by its sum of digits (20), we get a square (2856100 = 1690²).

Multiplying 142805 by its product of nonzero digits (320), we get a square (45697600 = 6760²).

The spelling of 142805 in words is "one hundred forty-two thousand, eight hundred five".