1906505 has 4 divisors (see below), whose sum is σ = 2287812. Its totient is φ = 1525200.

The previous prime is 1906481. The next prime is 1906511. The reversal of 1906505 is 5056091.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5056091 = 229 ⋅22079.

It can be written as a sum of positive squares in 2 ways, for example, as 1098304 + 808201 = 1048^2 + 899^2 .

It is not a de Polignac number, because 1906505 - 2¹⁴ = 1890121 is a prime.

It is a super-2 number, since 2×1906505² = 7269522630050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190646 + ... + 190655.

It is an arithmetic number, because the mean of its divisors is an integer number (571953).

2^1906505 is an apocalyptic number.

It is an amenable number.

1906505 is a deficient number, since it is larger than the sum of its proper divisors (381307).

1906505 is an equidigital number, since it uses as much as digits as its factorization.

1906505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381306.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 1906505 is about 1380.7624705213. The cubic root of 1906505 is about 123.9974201683.

The spelling of 1906505 in words is "one million, nine hundred six thousand, five hundred five".