20221811618 has 18 divisors (see below), whose sum is σ = 30549331827. Its totient is φ = 10039211520.

The previous prime is 20221811611. The next prime is 20221811629. The reversal of 20221811618 is 81611812202.

It can be written as a sum of positive squares in 5 ways, for example, as 1702140049 + 18519671569 = 41257^2 + 136087^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=100553.

It is a super-2 number, since 2×20221811618² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20221811611) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 38813198 + ... + 38813718.

Almost surely, 2^20221811618 is an apocalyptic number.

20221811618 is a deficient number, since it is larger than the sum of its proper divisors (10327520209).

20221811618 is an frugal number, since it uses more digits than its factorization.

20221811618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1430 (or 716 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 32.

Multiplying 20221811618 by its sum of digits (32), we get a square (647097971776 = 804424²).

The spelling of 20221811618 in words is "twenty billion, two hundred twenty-one million, eight hundred eleven thousand, six hundred eighteen".