135924721 has 2 divisors, whose sum is σ = 135924722. Its totient is φ = 135924720.

The previous prime is 135924713. The next prime is 135924749. The reversal of 135924721 is 127429531.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97298496 + 38626225 = 9864^2 + 6215^2 .

It is an emirp because it is prime and its reverse (127429531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 135924721 - 2³ = 135924713 is a prime.

It is not a weakly prime, because it can be changed into another prime (135924121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67962360 + 67962361.

It is an arithmetic number, because the mean of its divisors is an integer number (67962361).

Almost surely, 2^135924721 is an apocalyptic number.

It is an amenable number.

135924721 is a deficient number, since it is larger than the sum of its proper divisors (1).

135924721 is an equidigital number, since it uses as much as digits as its factorization.

135924721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 34.

The square root of 135924721 is about 11658.6757824377. The cubic root of 135924721 is about 514.1614165475.

The spelling of 135924721 in words is "one hundred thirty-five million, nine hundred twenty-four thousand, seven hundred twenty-one".