142157891 has 2 divisors, whose sum is σ = 142157892. Its totient is φ = 142157890.

The previous prime is 142157887. The next prime is 142157989. The reversal of 142157891 is 198751241.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 142157891 - 2² = 142157887 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (142157801) 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, 71078945 + 71078946.

It is an arithmetic number, because the mean of its divisors is an integer number (71078946).

Almost surely, 2^142157891 is an apocalyptic number.

142157891 is a deficient number, since it is larger than the sum of its proper divisors (1).

142157891 is an equidigital number, since it uses as much as digits as its factorization.

142157891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 38.

The square root of 142157891 is about 11922.9984064412. The cubic root of 142157891 is about 521.9036377176.

Adding to 142157891 its sum of digits (38), we get a square (142157929 = 11923²).

The spelling of 142157891 in words is "one hundred forty-two million, one hundred fifty-seven thousand, eight hundred ninety-one".