1961142072121 has 2 divisors, whose sum is σ = 1961142072122. Its totient is φ = 1961142072120.

The previous prime is 1961142072107. The next prime is 1961142072251. The reversal of 1961142072121 is 1212702411691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1393438593600 + 567703478521 = 1180440^2 + 753461^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961142072121 - 2¹³ = 1961142063929 is a prime.

It is not a weakly prime, because it can be changed into another prime (1961142072521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980571036060 + 980571036061.

It is an arithmetic number, because the mean of its divisors is an integer number (980571036061).

Almost surely, 2^{1961142072121} is an apocalyptic number.

It is an amenable number.

1961142072121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961142072121 is an equidigital number, since it uses as much as digits as its factorization.

1961142072121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 37.

The spelling of 1961142072121 in words is "one trillion, nine hundred sixty-one billion, one hundred forty-two million, seventy-two thousand, one hundred twenty-one".