1991964529 has 2 divisors, whose sum is σ = 1991964530. Its totient is φ = 1991964528.

The previous prime is 1991964517. The next prime is 1991964563. The reversal of 1991964529 is 9254691991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1039933504 + 952031025 = 32248^2 + 30855^2 .

It is a cyclic number.

It is not a de Polignac number, because 1991964529 - 2¹⁷ = 1991833457 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1991964529.

It is not a weakly prime, because it can be changed into another prime (1991964509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995982264 + 995982265.

It is an arithmetic number, because the mean of its divisors is an integer number (995982265).

Almost surely, 2^1991964529 is an apocalyptic number.

It is an amenable number.

1991964529 is a deficient number, since it is larger than the sum of its proper divisors (1).

1991964529 is an equidigital number, since it uses as much as digits as its factorization.

1991964529 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1574640, while the sum is 55.

The square root of 1991964529 is about 44631.4298336946. The cubic root of 1991964529 is about 1258.2314418947.

It can be divided in two parts, 19919 and 64529, that added together give a palindrome (84448).

The spelling of 1991964529 in words is "one billion, nine hundred ninety-one million, nine hundred sixty-four thousand, five hundred twenty-nine".