121756020409 has 2 divisors, whose sum is σ = 121756020410. Its totient is φ = 121756020408.

The previous prime is 121756020401. The next prime is 121756020439. The reversal of 121756020409 is 904020657121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89399206009 + 32356814400 = 298997^2 + 179880^2 .

It is a cyclic number.

It is not a de Polignac number, because 121756020409 - 2³ = 121756020401 is a prime.

It is not a weakly prime, because it can be changed into another prime (121756020401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60878010204 + 60878010205.

It is an arithmetic number, because the mean of its divisors is an integer number (60878010205).

Almost surely, 2^121756020409 is an apocalyptic number.

It is an amenable number.

121756020409 is a deficient number, since it is larger than the sum of its proper divisors (1).

121756020409 is an equidigital number, since it uses as much as digits as its factorization.

121756020409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 37.

The spelling of 121756020409 in words is "one hundred twenty-one billion, seven hundred fifty-six million, twenty thousand, four hundred nine".