1380905 has 4 divisors (see below), whose sum is σ = 1657092. Its totient is φ = 1104720.

The previous prime is 1380889. The next prime is 1380913. The reversal of 1380905 is 5090831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 238144 + 1142761 = 488^2 + 1069^2 .

It is not a de Polignac number, because 1380905 - 2⁴ = 1380889 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138086 + ... + 138095.

It is an arithmetic number, because the mean of its divisors is an integer number (414273).

2^1380905 is an apocalyptic number.

It is an amenable number.

1380905 is a deficient number, since it is larger than the sum of its proper divisors (276187).

1380905 is an equidigital number, since it uses as much as digits as its factorization.

1380905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276186.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1380905 is about 1175.1191428957. The cubic root of 1380905 is about 111.3579602574.

The spelling of 1380905 in words is "one million, three hundred eighty thousand, nine hundred five".