1961581002313 has 2 divisors, whose sum is σ = 1961581002314. Its totient is φ = 1961581002312.

The previous prime is 1961581002307. The next prime is 1961581002317. The reversal of 1961581002313 is 3132001851691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1499674550544 + 461906451769 = 1224612^2 + 679637^2 .

It is an emirp because it is prime and its reverse (3132001851691) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1961581002313 is a prime.

It is a super-2 number, since 2×1961581002313² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1961581002317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980790501156 + 980790501157.

It is an arithmetic number, because the mean of its divisors is an integer number (980790501157).

Almost surely, 2^{1961581002313} is an apocalyptic number.

It is an amenable number.

1961581002313 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961581002313 is an equidigital number, since it uses as much as digits as its factorization.

1961581002313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 40.

The spelling of 1961581002313 in words is "one trillion, nine hundred sixty-one billion, five hundred eighty-one million, two thousand, three hundred thirteen".