780021102121 has 4 divisors (see below), whose sum is σ = 790706322772. Its totient is φ = 769335881472.

The previous prime is 780021102079. The next prime is 780021102137. The reversal of 780021102121 is 121201120087.

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 450826302096 + 329194800025 = 671436^2 + 573755^2 .

It is a cyclic number.

It is not a de Polignac number, because 780021102121 - 2²⁷ = 779886884393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (780021105121) 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, 5342610216 + ... + 5342610361.

It is an arithmetic number, because the mean of its divisors is an integer number (197676580693).

Almost surely, 2^780021102121 is an apocalyptic number.

It is an amenable number.

780021102121 is a deficient number, since it is larger than the sum of its proper divisors (10685220651).

780021102121 is a wasteful number, since it uses less digits than its factorization.

780021102121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10685220650.

The product of its (nonzero) digits is 448, while the sum is 25.

The spelling of 780021102121 in words is "seven hundred eighty billion, twenty-one million, one hundred two thousand, one hundred twenty-one".