121689541 has 4 divisors (see below), whose sum is σ = 122495584. Its totient is φ = 120883500.

The previous prime is 121689521. The next prime is 121689563. The reversal of 121689541 is 145986121.

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: 145986121 = 4261 ⋅34261.

It is a cyclic number.

It is not a de Polignac number, because 121689541 - 2²⁵ = 88135109 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 121689541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121689521) 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, 402795 + ... + 403096.

It is an arithmetic number, because the mean of its divisors is an integer number (30623896).

Almost surely, 2^121689541 is an apocalyptic number.

It is an amenable number.

121689541 is a deficient number, since it is larger than the sum of its proper divisors (806043).

121689541 is an equidigital number, since it uses as much as digits as its factorization.

121689541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 806042.

The product of its digits is 17280, while the sum is 37.

The square root of 121689541 is about 11031.2982463534. The cubic root of 121689541 is about 495.5465052068.

The spelling of 121689541 in words is "one hundred twenty-one million, six hundred eighty-nine thousand, five hundred forty-one".