1200120021157 has 2 divisors, whose sum is σ = 1200120021158. Its totient is φ = 1200120021156.

The previous prime is 1200120021109. The next prime is 1200120021169. The reversal of 1200120021157 is 7511200210021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 831979312641 + 368140708516 = 912129^2 + 606746^2 .

It is a cyclic number.

It is not a de Polignac number, because 1200120021157 - 2¹⁹ = 1200119496869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1200120021187) 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, 600060010578 + 600060010579.

It is an arithmetic number, because the mean of its divisors is an integer number (600060010579).

Almost surely, 2^{1200120021157} is an apocalyptic number.

It is an amenable number.

1200120021157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200120021157 is an equidigital number, since it uses as much as digits as its factorization.

1200120021157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 280, while the sum is 22.

Adding to 1200120021157 its reverse (7511200210021), we get a palindrome (8711320231178).

The spelling of 1200120021157 in words is "one trillion, two hundred billion, one hundred twenty million, twenty-one thousand, one hundred fifty-seven".