135721043 has 2 divisors, whose sum is σ = 135721044. Its totient is φ = 135721042.

The previous prime is 135721039. The next prime is 135721051. The reversal of 135721043 is 340127531.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 135721043 - 2² = 135721039 is a prime.

It is not a weakly prime, because it can be changed into another prime (135721343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67860521 + 67860522.

It is an arithmetic number, because the mean of its divisors is an integer number (67860522).

Almost surely, 2^135721043 is an apocalyptic number.

135721043 is a deficient number, since it is larger than the sum of its proper divisors (1).

135721043 is an equidigital number, since it uses as much as digits as its factorization.

135721043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 135721043 is about 11649.9374676433. The cubic root of 135721043 is about 513.9044710858.

Adding to 135721043 its reverse (340127531), we get a palindrome (475848574).

The spelling of 135721043 in words is "one hundred thirty-five million, seven hundred twenty-one thousand, forty-three".