142817861 has 2 divisors, whose sum is σ = 142817862. Its totient is φ = 142817860.

The previous prime is 142817839. The next prime is 142817863. The reversal of 142817861 is 168718241.

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., 131217025 + 11600836 = 11455^2 + 3406^2 .

It is an emirp because it is prime and its reverse (168718241) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 142817861 - 2⁶ = 142817797 is a prime.

It is a Sophie Germain prime.

Together with 142817863, it forms a pair of twin primes.

It is a Chen 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 (142817863) 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, 71408930 + 71408931.

It is an arithmetic number, because the mean of its divisors is an integer number (71408931).

Almost surely, 2^142817861 is an apocalyptic number.

It is an amenable number.

142817861 is a deficient number, since it is larger than the sum of its proper divisors (1).

142817861 is an equidigital number, since it uses as much as digits as its factorization.

142817861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21504, while the sum is 38.

The square root of 142817861 is about 11950.6427023822. The cubic root of 142817861 is about 522.7100394076.

The spelling of 142817861 in words is "one hundred forty-two million, eight hundred seventeen thousand, eight hundred sixty-one".