121605541 has 4 divisors (see below), whose sum is σ = 123070752. Its totient is φ = 120140332.

The previous prime is 121605527. The next prime is 121605563. The reversal of 121605541 is 145506121.

It is a happy number.

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: 145506121 = 4517 ⋅32213.

It is a cyclic number.

It is not a de Polignac number, because 121605541 - 2⁷ = 121605413 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 (121605511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 732481 + ... + 732646.

It is an arithmetic number, because the mean of its divisors is an integer number (30767688).

Almost surely, 2^121605541 is an apocalyptic number.

It is an amenable number.

121605541 is a deficient number, since it is larger than the sum of its proper divisors (1465211).

121605541 is an equidigital number, since it uses as much as digits as its factorization.

121605541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1465210.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 121605541 is about 11027.4902403040. The cubic root of 121605541 is about 495.4324568188.

The spelling of 121605541 in words is "one hundred twenty-one million, six hundred five thousand, five hundred forty-one".