142178921 has 2 divisors, whose sum is σ = 142178922. Its totient is φ = 142178920.

The previous prime is 142178903. The next prime is 142178951. The reversal of 142178921 is 129871241.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 140090896 + 2088025 = 11836^2 + 1445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-142178921 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (142178951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71089460 + 71089461.

It is an arithmetic number, because the mean of its divisors is an integer number (71089461).

Almost surely, 2^142178921 is an apocalyptic number.

It is an amenable number.

142178921 is a deficient number, since it is larger than the sum of its proper divisors (1).

142178921 is an equidigital number, since it uses as much as digits as its factorization.

142178921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 35.

The square root of 142178921 is about 11923.8802828609. The cubic root of 142178921 is about 521.9293722307.

The spelling of 142178921 in words is "one hundred forty-two million, one hundred seventy-eight thousand, nine hundred twenty-one".