142187821 has 2 divisors, whose sum is σ = 142187822. Its totient is φ = 142187820.

The previous prime is 142187809. The next prime is 142187833. The reversal of 142187821 is 128781241.

It is a balanced prime because it is at equal distance from previous prime (142187809) and next prime (142187833).

It can be written as a sum of positive squares in only one way, i.e., 96138025 + 46049796 = 9805^2 + 6786^2 .

It is a cyclic number.

It is not a de Polignac number, because 142187821 - 2⁵ = 142187789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (142187321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71093910 + 71093911.

It is an arithmetic number, because the mean of its divisors is an integer number (71093911).

Almost surely, 2^142187821 is an apocalyptic number.

It is an amenable number.

142187821 is a deficient number, since it is larger than the sum of its proper divisors (1).

142187821 is an equidigital number, since it uses as much as digits as its factorization.

142187821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7168, while the sum is 34.

The square root of 142187821 is about 11924.2534776815. The cubic root of 142187821 is about 521.9402624397.

The spelling of 142187821 in words is "one hundred forty-two million, one hundred eighty-seven thousand, eight hundred twenty-one".