1961026913 has 4 divisors (see below), whose sum is σ = 1961136660. Its totient is φ = 1960917168.

The previous prime is 1961026909. The next prime is 1961026933. The reversal of 1961026913 is 3196201691.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3196201691 = 313 ⋅10211507.

It can be written as a sum of positive squares in 2 ways, for example, as 1724574784 + 236452129 = 41528^2 + 15377^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961026913 - 2² = 1961026909 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1961026933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21170 + ... + 66107.

It is an arithmetic number, because the mean of its divisors is an integer number (490284165).

Almost surely, 2^1961026913 is an apocalyptic number.

It is an amenable number.

1961026913 is a deficient number, since it is larger than the sum of its proper divisors (109747).

1961026913 is an equidigital number, since it uses as much as digits as its factorization.

1961026913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109746.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 1961026913 is about 44283.4835237699. The cubic root of 1961026913 is about 1251.6834731567.

The spelling of 1961026913 in words is "one billion, nine hundred sixty-one million, twenty-six thousand, nine hundred thirteen".