20218399111 has 16 divisors (see below), whose sum is σ = 21658624000. Its totient is φ = 18818720928.

The previous prime is 20218399109. The next prime is 20218399127. The reversal of 20218399111 is 11199381202.

It is a cyclic number.

It is not a de Polignac number, because 20218399111 - 2¹ = 20218399109 is a prime.

It is a super-2 number, since 2×20218399111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20218399211) 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, 207865 + ... + 289213.

It is an arithmetic number, because the mean of its divisors is an integer number (1353664000).

Almost surely, 2^20218399111 is an apocalyptic number.

20218399111 is a deficient number, since it is larger than the sum of its proper divisors (1440224889).

20218399111 is a wasteful number, since it uses less digits than its factorization.

20218399111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81598.

The product of its (nonzero) digits is 7776, while the sum is 37.

The spelling of 20218399111 in words is "twenty billion, two hundred eighteen million, three hundred ninety-nine thousand, one hundred eleven".