135721493 has 2 divisors, whose sum is σ = 135721494. Its totient is φ = 135721492.

The previous prime is 135721483. The next prime is 135721501. The reversal of 135721493 is 394127531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127757809 + 7963684 = 11303^2 + 2822^2 .

It is a cyclic number.

It is not a de Polignac number, because 135721493 - 2⁶ = 135721429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135721433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67860746 + 67860747.

It is an arithmetic number, because the mean of its divisors is an integer number (67860747).

Almost surely, 2^135721493 is an apocalyptic number.

It is an amenable number.

135721493 is a deficient number, since it is larger than the sum of its proper divisors (1).

135721493 is an equidigital number, since it uses as much as digits as its factorization.

135721493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 35.

The square root of 135721493 is about 11649.9567810357. The cubic root of 135721493 is about 513.9050390565.

The spelling of 135721493 in words is "one hundred thirty-five million, seven hundred twenty-one thousand, four hundred ninety-three".