142340021 has 2 divisors, whose sum is σ = 142340022. Its totient is φ = 142340020.

The previous prime is 142339979. The next prime is 142340027. The reversal of 142340021 is 120043241.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96628900 + 45711121 = 9830^2 + 6761^2 .

It is a cyclic number.

It is not a de Polignac number, because 142340021 - 2⁶ = 142339957 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (142340027) 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, 71170010 + 71170011.

It is an arithmetic number, because the mean of its divisors is an integer number (71170011).

Almost surely, 2^142340021 is an apocalyptic number.

It is an amenable number.

142340021 is a deficient number, since it is larger than the sum of its proper divisors (1).

142340021 is an equidigital number, since it uses as much as digits as its factorization.

142340021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 142340021 is about 11930.6337216428. The cubic root of 142340021 is about 522.1264269552.

Adding to 142340021 its reverse (120043241), we get a palindrome (262383262).

The spelling of 142340021 in words is "one hundred forty-two million, three hundred forty thousand, twenty-one".