121505653 has 4 divisors (see below), whose sum is σ = 123170188. Its totient is φ = 119841120.

The previous prime is 121505633. The next prime is 121505663. The reversal of 121505653 is 356505121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 356505121 = 7 ⋅50929303.

It can be written as a sum of positive squares in 2 ways, for example, as 105329169 + 16176484 = 10263^2 + 4022^2 .

It is a cyclic number.

It is not a de Polignac number, because 121505653 - 2⁹ = 121505141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121505633) 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, 832158 + ... + 832303.

It is an arithmetic number, because the mean of its divisors is an integer number (30792547).

Almost surely, 2^121505653 is an apocalyptic number.

It is an amenable number.

121505653 is a deficient number, since it is larger than the sum of its proper divisors (1664535).

121505653 is an equidigital number, since it uses as much as digits as its factorization.

121505653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1664534.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 121505653 is about 11022.9602648290. The cubic root of 121505653 is about 495.2967686121.

The spelling of 121505653 in words is "one hundred twenty-one million, five hundred five thousand, six hundred fifty-three".