20121323100 has 72 divisors (see below), whose sum is σ = 58575000960. Its totient is φ = 5332754880.

The previous prime is 20121323093. The next prime is 20121323149. The reversal of 20121323100 is 132312102.

It is a super-2 number, since 2×20121323100² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20121323100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 156840 + ... + 254639.

It is an arithmetic number, because the mean of its divisors is an integer number (813541680).

Almost surely, 2^20121323100 is an apocalyptic number.

20121323100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121323100 is an abundant number, since it is smaller than the sum of its proper divisors (38453677860).

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

20121323100 is a wasteful number, since it uses less digits than its factorization.

20121323100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411659 (or 411652 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 20121323100 its reverse (132312102), we get a palindrome (20253635202).

The spelling of 20121323100 in words is "twenty billion, one hundred twenty-one million, three hundred twenty-three thousand, one hundred".