134728721 has 2 divisors, whose sum is σ = 134728722. Its totient is φ = 134728720.

The previous prime is 134728709. The next prime is 134728777. The reversal of 134728721 is 127827431.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107019025 + 27709696 = 10345^2 + 5264^2 .

It is a cyclic number.

It is not a de Polignac number, because 134728721 - 2²⁶ = 67619857 is a prime.

It is not a weakly prime, because it can be changed into another prime (134728921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67364360 + 67364361.

It is an arithmetic number, because the mean of its divisors is an integer number (67364361).

Almost surely, 2^134728721 is an apocalyptic number.

It is an amenable number.

134728721 is a deficient number, since it is larger than the sum of its proper divisors (1).

134728721 is an equidigital number, since it uses as much as digits as its factorization.

134728721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18816, while the sum is 35.

The square root of 134728721 is about 11607.2701786423. The cubic root of 134728721 is about 512.6489383505.

The spelling of 134728721 in words is "one hundred thirty-four million, seven hundred twenty-eight thousand, seven hundred twenty-one".