121863409 has 4 divisors (see below), whose sum is σ = 121994404. Its totient is φ = 121732416.

The previous prime is 121863403. The next prime is 121863431. The reversal of 121863409 is 904368121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 31080625 + 90782784 = 5575^2 + 9528^2 .

It is a cyclic number.

It is not a de Polignac number, because 121863409 - 2¹¹ = 121861361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121863403) 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, 64092 + ... + 65965.

It is an arithmetic number, because the mean of its divisors is an integer number (30498601).

Almost surely, 2^121863409 is an apocalyptic number.

It is an amenable number.

121863409 is a deficient number, since it is larger than the sum of its proper divisors (130995).

121863409 is an equidigital number, since it uses as much as digits as its factorization.

121863409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130994.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 121863409 is about 11039.1761015032. The cubic root of 121863409 is about 495.7824024392.

The spelling of 121863409 in words is "one hundred twenty-one million, eight hundred sixty-three thousand, four hundred nine".