142121009 has 2 divisors, whose sum is σ = 142121010. Its totient is φ = 142121008.

The previous prime is 142120991. The next prime is 142121011. The reversal of 142121009 is 900121241.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107640625 + 34480384 = 10375^2 + 5872^2 .

It is an emirp because it is prime and its reverse (900121241) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 142121009 - 2⁸ = 142120753 is a prime.

It is a Sophie Germain prime.

Together with 142121011, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (142121069) 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, 71060504 + 71060505.

It is an arithmetic number, because the mean of its divisors is an integer number (71060505).

Almost surely, 2^142121009 is an apocalyptic number.

It is an amenable number.

142121009 is a deficient number, since it is larger than the sum of its proper divisors (1).

142121009 is an equidigital number, since it uses as much as digits as its factorization.

142121009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 142121009 is about 11921.4516314080. The cubic root of 142121009 is about 521.8584989058.

The spelling of 142121009 in words is "one hundred forty-two million, one hundred twenty-one thousand, nine".