121687855 has 4 divisors (see below), whose sum is σ = 146025432. Its totient is φ = 97350280.

The previous prime is 121687849. The next prime is 121687859. The reversal of 121687855 is 558786121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 558786121 = 4513 ⋅123817.

It is not a de Polignac number, because 121687855 - 2²³ = 113299247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121687859) 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, 12168781 + ... + 12168790.

It is an arithmetic number, because the mean of its divisors is an integer number (36506358).

Almost surely, 2^121687855 is an apocalyptic number.

121687855 is a deficient number, since it is larger than the sum of its proper divisors (24337577).

121687855 is an equidigital number, since it uses as much as digits as its factorization.

121687855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24337576.

The product of its digits is 134400, while the sum is 43.

The square root of 121687855 is about 11031.2218271595. The cubic root of 121687855 is about 495.5442166089.

The spelling of 121687855 in words is "one hundred twenty-one million, six hundred eighty-seven thousand, eight hundred fifty-five".