121561105 has 16 divisors (see below), whose sum is σ = 151896528. Its totient is φ = 93312000.

The previous prime is 121561093. The next prime is 121561147. The reversal of 121561105 is 501165121.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 82573569 + 38987536 = 9087^2 + 6244^2 .

It is not a de Polignac number, because 121561105 - 2⁷ = 121560977 is a prime.

It is a Duffinian 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, 7645 + ... + 17365.

It is an arithmetic number, because the mean of its divisors is an integer number (9493533).

Almost surely, 2^121561105 is an apocalyptic number.

It is an amenable number.

121561105 is a deficient number, since it is larger than the sum of its proper divisors (30335423).

121561105 is an equidigital number, since it uses as much as digits as its factorization.

121561105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9828.

The product of its (nonzero) digits is 300, while the sum is 22.

The square root of 121561105 is about 11025.4752732025. The cubic root of 121561105 is about 495.3721039803.

The spelling of 121561105 in words is "one hundred twenty-one million, five hundred sixty-one thousand, one hundred five".