121555505 has 8 divisors (see below), whose sum is σ = 145933224. Its totient is φ = 97200000.

The previous prime is 121555463. The next prime is 121555513. The reversal of 121555505 is 505555121.

It can be written as a sum of positive squares in 4 ways, for example, as 53129521 + 68425984 = 7289^2 + 8272^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121555505 - 2¹⁰ = 121554481 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10955 + ... + 19055.

It is an arithmetic number, because the mean of its divisors is an integer number (18241653).

Almost surely, 2^121555505 is an apocalyptic number.

It is an amenable number.

121555505 is a deficient number, since it is larger than the sum of its proper divisors (24377719).

121555505 is an equidigital number, since it uses as much as digits as its factorization.

121555505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11107.

The product of its (nonzero) digits is 6250, while the sum is 29.

The square root of 121555505 is about 11025.2213129715. The cubic root of 121555505 is about 495.3644970341.

The spelling of 121555505 in words is "one hundred twenty-one million, five hundred fifty-five thousand, five hundred five".