28720797965 has 16 divisors (see below), whose sum is σ = 34614252288. Its totient is φ = 22877202816.

The previous prime is 28720797961. The next prime is 28720797977. The reversal of 28720797965 is 56979702782.

It is a cyclic number.

It is not a de Polignac number, because 28720797965 - 2² = 28720797961 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28720797898 and 28720797907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28720797961) 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 15 ways as a sum of consecutive naturals, for example, 3142232 + ... + 3151358.

It is an arithmetic number, because the mean of its divisors is an integer number (2163390768).

Almost surely, 2^28720797965 is an apocalyptic number.

It is an amenable number.

28720797965 is a deficient number, since it is larger than the sum of its proper divisors (5893454323).

28720797965 is a wasteful number, since it uses less digits than its factorization.

28720797965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11788.

The product of its (nonzero) digits is 26671680, while the sum is 62.

The spelling of 28720797965 in words is "twenty-eight billion, seven hundred twenty million, seven hundred ninety-seven thousand, nine hundred sixty-five".