142135921 has 2 divisors, whose sum is σ = 142135922. Its totient is φ = 142135920.

The previous prime is 142135919. The next prime is 142135927. The reversal of 142135921 is 129531241.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138391696 + 3744225 = 11764^2 + 1935^2 .

It is a cyclic number.

It is not a de Polignac number, because 142135921 - 2¹ = 142135919 is a prime.

Together with 142135919, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 142135921.

It is not a weakly prime, because it can be changed into another prime (142135927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71067960 + 71067961.

It is an arithmetic number, because the mean of its divisors is an integer number (71067961).

Almost surely, 2^142135921 is an apocalyptic number.

It is an amenable number.

142135921 is a deficient number, since it is larger than the sum of its proper divisors (1).

142135921 is an equidigital number, since it uses as much as digits as its factorization.

142135921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 28.

The square root of 142135921 is about 11922.0770421936. The cubic root of 142135921 is about 521.8767502111.

The spelling of 142135921 in words is "one hundred forty-two million, one hundred thirty-five thousand, nine hundred twenty-one".