20001220123111 has 16 divisors (see below), whose sum is σ = 21444996029184. Its totient is φ = 18588190241664.

The previous prime is 20001220123099. The next prime is 20001220123133. The reversal of 20001220123111 is 11132102210002.

It is not a de Polignac number, because 20001220123111 - 2¹⁵ = 20001220090343 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 (20001220123811) 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, 15851685 + ... + 17066878.

It is an arithmetic number, because the mean of its divisors is an integer number (1340312251824).

Almost surely, 2^{20001220123111} is an apocalyptic number.

20001220123111 is a deficient number, since it is larger than the sum of its proper divisors (1443775906073).

20001220123111 is a wasteful number, since it uses less digits than its factorization.

20001220123111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32919030.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 20001220123111 its reverse (11132102210002), we get a palindrome (31133322333113).

The spelling of 20001220123111 in words is "twenty trillion, one billion, two hundred twenty million, one hundred twenty-three thousand, one hundred eleven".