121554721 has 2 divisors, whose sum is σ = 121554722. Its totient is φ = 121554720.

The previous prime is 121554703. The next prime is 121554733. The reversal of 121554721 is 127455121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121550625 + 4096 = 11025^2 + 64^2 .

It is a cyclic number.

It is not a de Polignac number, because 121554721 - 2¹⁹ = 121030433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121554721.

It is not a weakly prime, because it can be changed into another prime (121554781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60777360 + 60777361.

It is an arithmetic number, because the mean of its divisors is an integer number (60777361).

Almost surely, 2^121554721 is an apocalyptic number.

It is an amenable number.

121554721 is a deficient number, since it is larger than the sum of its proper divisors (1).

121554721 is an equidigital number, since it uses as much as digits as its factorization.

121554721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2800, while the sum is 28.

The square root of 121554721 is about 11025.1857580723. The cubic root of 121554721 is about 495.3634320429.

The spelling of 121554721 in words is "one hundred twenty-one million, five hundred fifty-four thousand, seven hundred twenty-one".