121431405406505 has 4 divisors (see below), whose sum is σ = 145717686487812. Its totient is φ = 97145124325200.

The previous prime is 121431405406379. The next prime is 121431405406601. The reversal of 121431405406505 is 505604504134121.

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 69844262714944 + 51587142691561 = 8357288^2 + 7182419^2 .

It is not a de Polignac number, because 121431405406505 - 2¹⁰ = 121431405405481 is a prime.

It is a Duffinian 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, 12143140540646 + ... + 12143140540655.

It is an arithmetic number, because the mean of its divisors is an integer number (36429421621953).

Almost surely, 2^{121431405406505} is an apocalyptic number.

It is an amenable number.

121431405406505 is a deficient number, since it is larger than the sum of its proper divisors (24286281081307).

121431405406505 is an equidigital number, since it uses as much as digits as its factorization.

121431405406505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24286281081306.

The product of its (nonzero) digits is 288000, while the sum is 41.

The spelling of 121431405406505 in words is "one hundred twenty-one trillion, four hundred thirty-one billion, four hundred five million, four hundred six thousand, five hundred five".