121653205 has 4 divisors (see below), whose sum is σ = 145983852. Its totient is φ = 97322560.

The previous prime is 121653193. The next prime is 121653209. The reversal of 121653205 is 502356121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 502356121 = 137 ⋅3666833.

It can be written as a sum of positive squares in 2 ways, for example, as 21613201 + 100040004 = 4649^2 + 10002^2 .

It is not a de Polignac number, because 121653205 - 2⁹ = 121652693 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121653205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121653209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12165316 + ... + 12165325.

It is an arithmetic number, because the mean of its divisors is an integer number (36495963).

Almost surely, 2^121653205 is an apocalyptic number.

It is an amenable number.

121653205 is a deficient number, since it is larger than the sum of its proper divisors (24330647).

121653205 is an equidigital number, since it uses as much as digits as its factorization.

121653205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24330646.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 121653205 is about 11029.6511730879. The cubic root of 121653205 is about 495.4971775759.

The spelling of 121653205 in words is "one hundred twenty-one million, six hundred fifty-three thousand, two hundred five".