135937721 has 2 divisors, whose sum is σ = 135937722. Its totient is φ = 135937720.

The previous prime is 135937717. The next prime is 135937733. The reversal of 135937721 is 127739531.

135937721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115326121 + 20611600 = 10739^2 + 4540^2 .

It is a cyclic number.

It is not a de Polignac number, because 135937721 - 2² = 135937717 is a prime.

It is not a weakly prime, because it can be changed into another prime (135931721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67968860 + 67968861.

It is an arithmetic number, because the mean of its divisors is an integer number (67968861).

Almost surely, 2^135937721 is an apocalyptic number.

It is an amenable number.

135937721 is a deficient number, since it is larger than the sum of its proper divisors (1).

135937721 is an equidigital number, since it uses as much as digits as its factorization.

135937721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39690, while the sum is 38.

The square root of 135937721 is about 11659.2332938320. The cubic root of 135937721 is about 514.1778076922.

The spelling of 135937721 in words is "one hundred thirty-five million, nine hundred thirty-seven thousand, seven hundred twenty-one".