8720121311 has 4 divisors (see below), whose sum is σ = 9512859624. Its totient is φ = 7927383000.

The previous prime is 8720121301. The next prime is 8720121337. The reversal of 8720121311 is 1131210278.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8720121311 - 2¹⁴ = 8720104927 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 (8720121301) 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, 396369140 + ... + 396369161.

It is an arithmetic number, because the mean of its divisors is an integer number (2378214906).

Almost surely, 2^8720121311 is an apocalyptic number.

8720121311 is a deficient number, since it is larger than the sum of its proper divisors (792738313).

8720121311 is a wasteful number, since it uses less digits than its factorization.

8720121311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792738312.

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 8720121311 is about 93381.5897862100. The cubic root of 8720121311 is about 2058.2944779230.

Adding to 8720121311 its reverse (1131210278), we get a palindrome (9851331589).

It can be divided in two parts, 8720 and 121311, that added together give a palindrome (130031).

The spelling of 8720121311 in words is "eight billion, seven hundred twenty million, one hundred twenty-one thousand, three hundred eleven".