1961821024129 has 4 divisors (see below), whose sum is σ = 1961824149076. Its totient is φ = 1961817899184.

The previous prime is 1961821024039. The next prime is 1961821024181. The reversal of 1961821024129 is 9214201281691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1200306492225 + 761514531904 = 1095585^2 + 872648^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961821024129 - 2²⁹ = 1961284153217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1961821024829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 257454 + ... + 1997479.

It is an arithmetic number, because the mean of its divisors is an integer number (490456037269).

Almost surely, 2^{1961821024129} is an apocalyptic number.

It is an amenable number.

1961821024129 is a deficient number, since it is larger than the sum of its proper divisors (3124947).

1961821024129 is an equidigital number, since it uses as much as digits as its factorization.

1961821024129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3124946.

The product of its (nonzero) digits is 124416, while the sum is 46.

The spelling of 1961821024129 in words is "one trillion, nine hundred sixty-one billion, eight hundred twenty-one million, twenty-four thousand, one hundred twenty-nine".