12765446221 has 4 divisors (see below), whose sum is σ = 13925941344. Its totient is φ = 11604951100.

The previous prime is 12765446219. The next prime is 12765446329. The reversal of 12765446221 is 12264456721.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12765446221 - 2¹ = 12765446219 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 (12765446201) 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, 580247545 + ... + 580247566.

It is an arithmetic number, because the mean of its divisors is an integer number (3481485336).

Almost surely, 2^12765446221 is an apocalyptic number.

12765446221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12765446221 is a deficient number, since it is larger than the sum of its proper divisors (1160495123).

12765446221 is a wasteful number, since it uses less digits than its factorization.

12765446221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1160495122.

The product of its digits is 161280, while the sum is 40.

The spelling of 12765446221 in words is "twelve billion, seven hundred sixty-five million, four hundred forty-six thousand, two hundred twenty-one".