121720069 has 2 divisors, whose sum is σ = 121720070. Its totient is φ = 121720068.

The previous prime is 121720031. The next prime is 121720073. The reversal of 121720069 is 960027121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 113529025 + 8191044 = 10655^2 + 2862^2 .

It is a cyclic number.

It is not a de Polignac number, because 121720069 - 2⁹ = 121719557 is a prime.

It is a super-2 number, since 2×121720069² = 29631550394729522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121720369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60860034 + 60860035.

It is an arithmetic number, because the mean of its divisors is an integer number (60860035).

Almost surely, 2^121720069 is an apocalyptic number.

It is an amenable number.

121720069 is a deficient number, since it is larger than the sum of its proper divisors (1).

121720069 is an equidigital number, since it uses as much as digits as its factorization.

121720069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 121720069 is about 11032.6818589135. The cubic root of 121720069 is about 495.5879406463.

The spelling of 121720069 in words is "one hundred twenty-one million, seven hundred twenty thousand, sixty-nine".