101221210100 has 72 divisors (see below), whose sum is σ = 224543654328. Its totient is φ = 39594124800.

The previous prime is 101221210007. The next prime is 101221210213. The reversal of 101221210100 is 1012122101.

It can be written as a sum of positive squares in 12 ways, for example, as 27943802896 + 73277407204 = 167164^2 + 270698^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1007342 + ... + 1103258.

Almost surely, 2^101221210100 is an apocalyptic number.

101221210100 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 101221210100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112271827164).

101221210100 is an abundant number, since it is smaller than the sum of its proper divisors (123322444228).

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

101221210100 is a wasteful number, since it uses less digits than its factorization.

101221210100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96165 (or 96158 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 101221210100 its reverse (1012122101), we get a palindrome (102233332201).

The spelling of 101221210100 in words is "one hundred one billion, two hundred twenty-one million, two hundred ten thousand, one hundred".