142781021 has 2 divisors, whose sum is σ = 142781022. Its totient is φ = 142781020.

The previous prime is 142780933. The next prime is 142781059. The reversal of 142781021 is 120187241.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114276100 + 28504921 = 10690^2 + 5339^2 .

It is an emirp because it is prime and its reverse (120187241) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-142781021 is a prime.

It is equal to p_8060336 and since 142781021 and 8060336 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (142781081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71390510 + 71390511.

It is an arithmetic number, because the mean of its divisors is an integer number (71390511).

Almost surely, 2^142781021 is an apocalyptic number.

It is an amenable number.

142781021 is a deficient number, since it is larger than the sum of its proper divisors (1).

142781021 is an equidigital number, since it uses as much as digits as its factorization.

142781021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 142781021 is about 11949.1012632750. The cubic root of 142781021 is about 522.6650910290.

The spelling of 142781021 in words is "one hundred forty-two million, seven hundred eighty-one thousand, twenty-one".