121636729 has 4 divisors (see below), whose sum is σ = 121732240. Its totient is φ = 121541220.

The previous prime is 121636721. The next prime is 121636733. The reversal of 121636729 is 927636121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 927636121 = 503 ⋅1844207.

It is a cyclic number.

It is not a de Polignac number, because 121636729 - 2³ = 121636721 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121636721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45819 + ... + 48400.

It is an arithmetic number, because the mean of its divisors is an integer number (30433060).

Almost surely, 2^121636729 is an apocalyptic number.

It is an amenable number.

121636729 is a deficient number, since it is larger than the sum of its proper divisors (95511).

121636729 is an equidigital number, since it uses as much as digits as its factorization.

121636729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95510.

The product of its digits is 27216, while the sum is 37.

The square root of 121636729 is about 11028.9042520098. The cubic root of 121636729 is about 495.4748074841.

The spelling of 121636729 in words is "one hundred twenty-one million, six hundred thirty-six thousand, seven hundred twenty-nine".