12920006221 has 4 divisors (see below), whose sum is σ = 12933737244. Its totient is φ = 12906275200.

The previous prime is 12920006219. The next prime is 12920006261. The reversal of 12920006221 is 12260002921.

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 9422584900 + 3497421321 = 97070^2 + 59139^2 .

It is a cyclic number.

It is not a de Polignac number, because 12920006221 - 2¹ = 12920006219 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 (12920006261) 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, 6864100 + ... + 6865981.

It is an arithmetic number, because the mean of its divisors is an integer number (3233434311).

Almost surely, 2^12920006221 is an apocalyptic number.

It is an amenable number.

12920006221 is a deficient number, since it is larger than the sum of its proper divisors (13731023).

12920006221 is an equidigital number, since it uses as much as digits as its factorization.

12920006221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13731022.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 12920006221 in words is "twelve billion, nine hundred twenty million, six thousand, two hundred twenty-one".