123321221100 has 432 divisors, whose sum is σ = 498550590720. Its totient is φ = 24741158400.

The previous prime is 123321221087. The next prime is 123321221113. The reversal of 123321221100 is 1122123321.

123321221100 is a `hidden beast` number, since 1 + 23 + 321 + 221 + 100 = 666.

It is an interprime number because it is at equal distance from previous prime (123321221087) and next prime (123321221113).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1979019 + ... + 2040381.

Almost surely, 2^123321221100 is an apocalyptic number.

123321221100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123321221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249275295360).

123321221100 is an abundant number, since it is smaller than the sum of its proper divisors (375229369620).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123321221100 is a wasteful number, since it uses less digits than its factorization.

123321221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61430 (or 61420 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 123321221100 its reverse (1122123321), we get a palindrome (124443344421).

The spelling of 123321221100 in words is "one hundred twenty-three billion, three hundred twenty-one million, two hundred twenty-one thousand, one hundred".