1405891 has 4 divisors (see below), whose sum is σ = 1454400. Its totient is φ = 1357384.

The previous prime is 1405879. The next prime is 1405919. The reversal of 1405891 is 1985041.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1405891 is a prime.

It is a Duffinian number.

1405891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1405801) 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, 24211 + ... + 24268.

It is an arithmetic number, because the mean of its divisors is an integer number (363600).

2^1405891 is an apocalyptic number.

1405891 is a deficient number, since it is larger than the sum of its proper divisors (48509).

1405891 is an equidigital number, since it uses as much as digits as its factorization.

1405891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48508.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 1405891 is about 1185.7027452106. The cubic root of 1405891 is about 112.0255840789.

The spelling of 1405891 in words is "one million, four hundred five thousand, eight hundred ninety-one".