121550405 has 4 divisors (see below), whose sum is σ = 145860492. Its totient is φ = 97240320.

The previous prime is 121550399. The next prime is 121550419. The reversal of 121550405 is 504055121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69739201 + 51811204 = 8351^2 + 7198^2 .

It is not a de Polignac number, because 121550405 - 2⁴ = 121550389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12155036 + ... + 12155045.

It is an arithmetic number, because the mean of its divisors is an integer number (36465123).

Almost surely, 2^121550405 is an apocalyptic number.

It is an amenable number.

121550405 is a deficient number, since it is larger than the sum of its proper divisors (24310087).

121550405 is an equidigital number, since it uses as much as digits as its factorization.

121550405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24310086.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 121550405 is about 11024.9900226712. The cubic root of 121550405 is about 495.3575690762.

The spelling of 121550405 in words is "one hundred twenty-one million, five hundred fifty thousand, four hundred five".