1906591 has 4 divisors (see below), whose sum is σ = 1913752. Its totient is φ = 1899432.

The previous prime is 1906589. The next prime is 1906603. The reversal of 1906591 is 1956091.

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

It is a cyclic number.

It is not a de Polignac number, because 1906591 - 2¹ = 1906589 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 (1906511) 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, 3165 + ... + 3718.

It is an arithmetic number, because the mean of its divisors is an integer number (478438).

2^1906591 is an apocalyptic number.

1906591 is a deficient number, since it is larger than the sum of its proper divisors (7161).

1906591 is an equidigital number, since it uses as much as digits as its factorization.

1906591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7160.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 1906591 is about 1380.7936123838. The cubic root of 1906591 is about 123.9992845952. Note that the first 3 decimals are identical.

The spelling of 1906591 in words is "one million, nine hundred six thousand, five hundred ninety-one".