1991648653 has 2 divisors, whose sum is σ = 1991648654. Its totient is φ = 1991648652.

The previous prime is 1991648531. The next prime is 1991648657. The reversal of 1991648653 is 3568461991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1991569129 + 79524 = 44627^2 + 282^2 .

It is a cyclic number.

It is not a de Polignac number, because 1991648653 - 2¹³ = 1991640461 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1991648653.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1991648657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995824326 + 995824327.

It is an arithmetic number, because the mean of its divisors is an integer number (995824327).

Almost surely, 2^1991648653 is an apocalyptic number.

It is an amenable number.

1991648653 is a deficient number, since it is larger than the sum of its proper divisors (1).

1991648653 is an equidigital number, since it uses as much as digits as its factorization.

1991648653 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 52.

The square root of 1991648653 is about 44627.8909763838. The cubic root of 1991648653 is about 1258.1649303146.

The spelling of 1991648653 in words is "one billion, nine hundred ninety-one million, six hundred forty-eight thousand, six hundred fifty-three".