121391729 has 8 divisors (see below), whose sum is σ = 122215080. Its totient is φ = 120571776.

The previous prime is 121391707. The next prime is 121391737. The reversal of 121391729 is 927193121.

It can be written as a sum of positive squares in 4 ways, for example, as 1270129 + 120121600 = 1127^2 + 10960^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121391729 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121391759) 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, 121259 + ... + 122255.

It is an arithmetic number, because the mean of its divisors is an integer number (15276885).

Almost surely, 2^121391729 is an apocalyptic number.

It is an amenable number.

121391729 is a deficient number, since it is larger than the sum of its proper divisors (823351).

121391729 is an equidigital number, since it uses as much as digits as its factorization.

121391729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1699.

The product of its digits is 6804, while the sum is 35.

The square root of 121391729 is about 11017.7914756089. The cubic root of 121391729 is about 495.1419230501.

The spelling of 121391729 in words is "one hundred twenty-one million, three hundred ninety-one thousand, seven hundred twenty-nine".