1901491 has 4 divisors (see below), whose sum is σ = 1921192. Its totient is φ = 1881792.

The previous prime is 1901489. The next prime is 1901507. The reversal of 1901491 is 1941091.

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 1901491 - 2¹ = 1901489 is a prime.

It is a Duffinian number.

1901491 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1901461) 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, 9705 + ... + 9898.

It is an arithmetic number, because the mean of its divisors is an integer number (480298).

2^1901491 is an apocalyptic number.

1901491 is a deficient number, since it is larger than the sum of its proper divisors (19701).

1901491 is an equidigital number, since it uses as much as digits as its factorization.

1901491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19700.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 1901491 is about 1378.9456116903. The cubic root of 1901491 is about 123.8886226751. Note that the first 3 decimals are identical.

It can be divided in two parts, 190 and 1491, that added together give a square (1681 = 41²).

The spelling of 1901491 in words is "one million, nine hundred one thousand, four hundred ninety-one".