121503643 has 4 divisors (see below), whose sum is σ = 123495568. Its totient is φ = 119511720.

The previous prime is 121503611. The next prime is 121503647. The reversal of 121503643 is 346305121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346305121 = 619 ⋅559459.

It is a cyclic number.

It is not a de Polignac number, because 121503643 - 2⁵ = 121503611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121503647) 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, 995871 + ... + 995992.

It is an arithmetic number, because the mean of its divisors is an integer number (30873892).

Almost surely, 2^121503643 is an apocalyptic number.

121503643 is a deficient number, since it is larger than the sum of its proper divisors (1991925).

121503643 is an equidigital number, since it uses as much as digits as its factorization.

121503643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1991924.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 121503643 is about 11022.8690911214. The cubic root of 121503643 is about 495.2940374580.

Adding to 121503643 its reverse (346305121), we get a palindrome (467808764).

The spelling of 121503643 in words is "one hundred twenty-one million, five hundred three thousand, six hundred forty-three".