121366721 has 4 divisors (see below), whose sum is σ = 138704832. Its totient is φ = 104028612.

The previous prime is 121366669. The next prime is 121366727. The reversal of 121366721 is 127663121.

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: 127663121 = 9311 ⋅13711.

It is a cyclic number.

It is not a de Polignac number, because 121366721 - 2⁶ = 121366657 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121366727) 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, 8669045 + ... + 8669058.

It is an arithmetic number, because the mean of its divisors is an integer number (34676208).

Almost surely, 2^121366721 is an apocalyptic number.

It is an amenable number.

121366721 is a deficient number, since it is larger than the sum of its proper divisors (17338111).

121366721 is an equidigital number, since it uses as much as digits as its factorization.

121366721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17338110.

The product of its digits is 3024, while the sum is 29.

The square root of 121366721 is about 11016.6565254618. The cubic root of 121366721 is about 495.1079191968.

The spelling of 121366721 in words is "one hundred twenty-one million, three hundred sixty-six thousand, seven hundred twenty-one".