21207611470205 has 4 divisors (see below), whose sum is σ = 25449133764252. Its totient is φ = 16966089176160.

The previous prime is 21207611470189. The next prime is 21207611470219. The reversal of 21207611470205 is 50207411670212.

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 11159053827289 + 10048557642916 = 3340517^2 + 3169946^2 .

It is not a de Polignac number, because 21207611470205 - 2⁴ = 21207611470189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2120761147016 + ... + 2120761147025.

It is an arithmetic number, because the mean of its divisors is an integer number (6362283441063).

Almost surely, 2^{21207611470205} is an apocalyptic number.

It is an amenable number.

21207611470205 is a deficient number, since it is larger than the sum of its proper divisors (4241522294047).

21207611470205 is an equidigital number, since it uses as much as digits as its factorization.

21207611470205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4241522294046.

The product of its (nonzero) digits is 47040, while the sum is 38.

The spelling of 21207611470205 in words is "twenty-one trillion, two hundred seven billion, six hundred eleven million, four hundred seventy thousand, two hundred five".