1991527 has 2 divisors, whose sum is σ = 1991528. Its totient is φ = 1991526.

The previous prime is 1991519. The next prime is 1991551. The reversal of 1991527 is 7251991.

1991527 is nontrivially palindromic in base 6.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1991527 - 2³ = 1991519 is a prime.

1991527 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1991492 and 1991501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1991597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995763 + 995764.

It is an arithmetic number, because the mean of its divisors is an integer number (995764).

2^1991527 is an apocalyptic number.

1991527 is a deficient number, since it is larger than the sum of its proper divisors (1).

1991527 is an equidigital number, since it uses as much as digits as its factorization.

1991527 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5670, while the sum is 34.

The square root of 1991527 is about 1411.2147249799. The cubic root of 1991527 is about 125.8139312902.

The spelling of 1991527 in words is "one million, nine hundred ninety-one thousand, five hundred twenty-seven".