121705618 has 16 divisors (see below), whose sum is σ = 193507704. Its totient is φ = 57210880.

The previous prime is 121705603. The next prime is 121705651. The reversal of 121705618 is 816507121.

It can be written as a sum of positive squares in 4 ways, for example, as 121594729 + 110889 = 11027^2 + 333^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 121705618.

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, 49146 + ... + 51562.

Almost surely, 2^121705618 is an apocalyptic number.

121705618 is a deficient number, since it is larger than the sum of its proper divisors (71802086).

121705618 is a wasteful number, since it uses less digits than its factorization.

121705618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3917.

The product of its (nonzero) digits is 3360, while the sum is 31.

The square root of 121705618 is about 11032.0269216495. The cubic root of 121705618 is about 495.5683272694.

It can be divided in two parts, 121 and 705618, that multiplied together give a triangular number (85379778 = T₁₃₀₆₇).

The spelling of 121705618 in words is "one hundred twenty-one million, seven hundred five thousand, six hundred eighteen".