1491851 has 2 divisors, whose sum is σ = 1491852. Its totient is φ = 1491850.

The previous prime is 1491839. The next prime is 1491859. The reversal of 1491851 is 1581941.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1491851 - 2¹⁸ = 1229707 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1491859) 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 as a sum of consecutive naturals, namely, 745925 + 745926.

It is an arithmetic number, because the mean of its divisors is an integer number (745926).

2^1491851 is an apocalyptic number.

1491851 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491851 is an equidigital number, since it uses as much as digits as its factorization.

1491851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 29.

The square root of 1491851 is about 1221.4135253877. The cubic root of 1491851 is about 114.2637526997.

The spelling of 1491851 in words is "one million, four hundred ninety-one thousand, eight hundred fifty-one".