1905997 has 4 divisors (see below), whose sum is σ = 1911196. Its totient is φ = 1900800.

The previous prime is 1905983. The next prime is 1906007. The reversal of 1905997 is 7995091.

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 1190281 + 715716 = 1091^2 + 846^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1905997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1905697) by changing a digit.

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, 2004 + ... + 2797.

It is an arithmetic number, because the mean of its divisors is an integer number (477799).

2^1905997 is an apocalyptic number.

It is an amenable number.

1905997 is a deficient number, since it is larger than the sum of its proper divisors (5199).

1905997 is an equidigital number, since it uses as much as digits as its factorization.

1905997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5198.

The product of its (nonzero) digits is 25515, while the sum is 40.

The square root of 1905997 is about 1380.5785019332. The cubic root of 1905997 is about 123.9864058979.

The spelling of 1905997 in words is "one million, nine hundred five thousand, nine hundred ninety-seven".