20121809077789 has 16 divisors (see below), whose sum is σ = 21109364519040. Its totient is φ = 19153847160000.

The previous prime is 20121809077759. The next prime is 20121809077861. The reversal of 20121809077789 is 98777090812102.

It is a cyclic number.

It is not a de Polignac number, because 20121809077789 - 2⁵ = 20121809077757 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 (20121809077759) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105780814 + ... + 105970864.

It is an arithmetic number, because the mean of its divisors is an integer number (1319335282440).

Almost surely, 2^{20121809077789} is an apocalyptic number.

20121809077789 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20121809077789 is a deficient number, since it is larger than the sum of its proper divisors (987555441251).

20121809077789 is a wasteful number, since it uses less digits than its factorization.

20121809077789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241572.

The product of its (nonzero) digits is 7112448, while the sum is 61.

The spelling of 20121809077789 in words is "twenty trillion, one hundred twenty-one billion, eight hundred nine million, seventy-seven thousand, seven hundred eighty-nine".