221012123100 has 72 divisors (see below), whose sum is σ = 640886324400. Its totient is φ = 58805268480.

The previous prime is 221012123081. The next prime is 221012123117. The reversal of 221012123100 is 1321210122.

It is a super-2 number, since 2×221012123100² (a number of 23 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 221012123100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 685687 + ... + 955086.

It is an arithmetic number, because the mean of its divisors is an integer number (8901198950).

Almost surely, 2^221012123100 is an apocalyptic number.

221012123100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221012123100 is an abundant number, since it is smaller than the sum of its proper divisors (419874201300).

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

221012123100 is a wasteful number, since it uses less digits than its factorization.

221012123100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1641239 (or 1641232 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 221012123100 its reverse (1321210122), we get a palindrome (222333333222).

The spelling of 221012123100 in words is "two hundred twenty-one billion, twelve million, one hundred twenty-three thousand, one hundred".