121538729 has 8 divisors (see below), whose sum is σ = 138587400. Its totient is φ = 105590016.

The previous prime is 121538717. The next prime is 121538749. The reversal of 121538729 is 927835121.

It can be written as a sum of positive squares in 4 ways, for example, as 6620329 + 114918400 = 2573^2 + 10720^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121538729 - 2²⁴ = 104761513 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 121538692 and 121538701.

It is not an unprimeable number, because it can be changed into a prime (121538749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 274754 + ... + 275195.

It is an arithmetic number, because the mean of its divisors is an integer number (17323425).

Almost surely, 2^121538729 is an apocalyptic number.

It is an amenable number.

121538729 is a deficient number, since it is larger than the sum of its proper divisors (17048671).

121538729 is a wasteful number, since it uses less digits than its factorization.

121538729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549979.

The product of its digits is 30240, while the sum is 38.

The square root of 121538729 is about 11024.4604856655. The cubic root of 121538729 is about 495.3417073981.

The spelling of 121538729 in words is "one hundred twenty-one million, five hundred thirty-eight thousand, seven hundred twenty-nine".