142939681 has 2 divisors, whose sum is σ = 142939682. Its totient is φ = 142939680.

The previous prime is 142939669. The next prime is 142939691. The reversal of 142939681 is 186939241.

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., 138274081 + 4665600 = 11759^2 + 2160^2 .

It is an emirp because it is prime and its reverse (186939241) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 142939681 - 2⁵ = 142939649 is a prime.

It is a super-2 number, since 2×142939681² = 40863504808763522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (142939631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71469840 + 71469841.

It is an arithmetic number, because the mean of its divisors is an integer number (71469841).

Almost surely, 2^142939681 is an apocalyptic number.

It is an amenable number.

142939681 is a deficient number, since it is larger than the sum of its proper divisors (1).

142939681 is an equidigital number, since it uses as much as digits as its factorization.

142939681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 43.

The square root of 142939681 is about 11955.7384129965. The cubic root of 142939681 is about 522.8586166240.

The spelling of 142939681 in words is "one hundred forty-two million, nine hundred thirty-nine thousand, six hundred eighty-one".