123721840066 has 48 divisors (see below), whose sum is σ = 216829205208. Its totient is φ = 52722728960.

The previous prime is 123721840061. The next prime is 123721840091. The reversal of 123721840066 is 660048127321.

It can be written as a sum of positive squares in 4 ways, for example, as 122829921841 + 891918225 = 350471^2 + 29865^2 .

It is not an unprimeable number, because it can be changed into a prime (123721840061) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 998790 + ... + 1115806.

Almost surely, 2^123721840066 is an apocalyptic number.

123721840066 is a deficient number, since it is larger than the sum of its proper divisors (93107365142).

123721840066 is a wasteful number, since it uses less digits than its factorization.

123721840066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117315 (or 117304 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

Adding to 123721840066 its reverse (660048127321), we get a palindrome (783769967387).

The spelling of 123721840066 in words is "one hundred twenty-three billion, seven hundred twenty-one million, eight hundred forty thousand, sixty-six".