121643745 has 24 divisors (see below), whose sum is σ = 198440256. Its totient is φ = 63630528.

The previous prime is 121643737. The next prime is 121643747. The reversal of 121643745 is 547346121.

It is not a de Polignac number, because 121643745 - 2³ = 121643737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121643747) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40692 + ... + 43578.

It is an arithmetic number, because the mean of its divisors is an integer number (8268344).

Almost surely, 2^121643745 is an apocalyptic number.

121643745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121643745 is a deficient number, since it is larger than the sum of its proper divisors (76796511).

121643745 is an equidigital number, since it uses as much as digits as its factorization.

121643745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3001 (or 2948 counting only the distinct ones).

The product of its digits is 20160, while the sum is 33.

The square root of 121643745 is about 11029.2223207260. Note that the first 3 decimals coincide. The cubic root of 121643745 is about 495.4843336210.

Adding to 121643745 its reverse (547346121), we get a palindrome (668989866).

The spelling of 121643745 in words is "one hundred twenty-one million, six hundred forty-three thousand, seven hundred forty-five".