1279779197221 has 8 divisors (see below), whose sum is σ = 1472420937600. Its totient is φ = 1089591492048.

The previous prime is 1279779197209. The next prime is 1279779197227. The reversal of 1279779197221 is 1227919779721.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1279779197221 - 2¹¹ = 1279779195173 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 (1279779197227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 613507681 + ... + 613509766.

It is an arithmetic number, because the mean of its divisors is an integer number (184052617200).

Almost surely, 2^{1279779197221} is an apocalyptic number.

It is an amenable number.

1279779197221 is a deficient number, since it is larger than the sum of its proper divisors (192641740379).

1279779197221 is a wasteful number, since it uses less digits than its factorization.

1279779197221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227017603.

The product of its digits is 14002632, while the sum is 64.

The spelling of 1279779197221 in words is "one trillion, two hundred seventy-nine billion, seven hundred seventy-nine million, one hundred ninety-seven thousand, two hundred twenty-one".