121816605 has 16 divisors (see below), whose sum is σ = 196838784. Its totient is φ = 64324800.

The previous prime is 121816571. The next prime is 121816613. The reversal of 121816605 is 506618121.

It is not a de Polignac number, because 121816605 - 2¹¹ = 121814557 is a prime.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 38689 + ... + 41718.

It is an arithmetic number, because the mean of its divisors is an integer number (12302424).

Almost surely, 2^121816605 is an apocalyptic number.

121816605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121816605 is a deficient number, since it is larger than the sum of its proper divisors (75022179).

121816605 is a wasteful number, since it uses less digits than its factorization.

121816605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80516.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 121816605 is about 11037.0559933345. The cubic root of 121816605 is about 495.7189227037.

The spelling of 121816605 in words is "one hundred twenty-one million, eight hundred sixteen thousand, six hundred five".