1961079505501 has 2 divisors, whose sum is σ = 1961079505502. Its totient is φ = 1961079505500.

The previous prime is 1961079505499. The next prime is 1961079505537. The reversal of 1961079505501 is 1055059701691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1284819983001 + 676259522500 = 1133499^2 + 822350^2 .

It is an emirp because it is prime and its reverse (1055059701691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1961079505501 - 2¹ = 1961079505499 is a prime.

It is a super-2 number, since 2×1961079505501² (a number of 25 digits) contains 22 as substring.

Together with 1961079505499, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1961079505571) 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 as a sum of consecutive naturals, namely, 980539752750 + 980539752751.

It is an arithmetic number, because the mean of its divisors is an integer number (980539752751).

Almost surely, 2^{1961079505501} is an apocalyptic number.

It is an amenable number.

1961079505501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961079505501 is an equidigital number, since it uses as much as digits as its factorization.

1961079505501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 425250, while the sum is 49.

The spelling of 1961079505501 in words is "one trillion, nine hundred sixty-one billion, seventy-nine million, five hundred five thousand, five hundred one".