20311221111999 has 4 divisors (see below), whose sum is σ = 27081628149336. Its totient is φ = 13540814074664.

The previous prime is 20311221111997. The next prime is 20311221112003. The reversal of 20311221111999 is 99911112211302.

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 20311221111999 - 2¹ = 20311221111997 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20311221111999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20311221111997) 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, 3385203518664 + ... + 3385203518669.

It is an arithmetic number, because the mean of its divisors is an integer number (6770407037334).

Almost surely, 2^{20311221111999} is an apocalyptic number.

20311221111999 is a deficient number, since it is larger than the sum of its proper divisors (6770407037337).

20311221111999 is an equidigital number, since it uses as much as digits as its factorization.

20311221111999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6770407037336.

The product of its (nonzero) digits is 17496, while the sum is 42.

The spelling of 20311221111999 in words is "twenty trillion, three hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, nine hundred ninety-nine".