101221100028 has 36 divisors (see below), whose sum is σ = 260692083288. Its totient is φ = 33103755360.

The previous prime is 101221100027. The next prime is 101221100041. The reversal of 101221100028 is 820001122101.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×101221100028² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101221100027) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 26523538 + ... + 26527353.

It is an arithmetic number, because the mean of its divisors is an integer number (7241446758).

Almost surely, 2^101221100028 is an apocalyptic number.

101221100028 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

101221100028 is an abundant number, since it is smaller than the sum of its proper divisors (159470983260).

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

101221100028 is a wasteful number, since it uses less digits than its factorization.

101221100028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53050954 (or 53050949 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 101221100028 its reverse (820001122101), we get a palindrome (921222222129).

The spelling of 101221100028 in words is "one hundred one billion, two hundred twenty-one million, one hundred thousand, twenty-eight".