221001020100 has 162 divisors, whose sum is σ = 805811975514. Its totient is φ = 50514508800.

The previous prime is 221001020087. The next prime is 221001020117. The reversal of 221001020100 is 1020100122.

It can be written as a sum of positive squares in 3 ways, for example, as 21411883584 + 199589136516 = 146328^2 + 446754^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 2461581 + ... + 2549780.

It is an arithmetic number, because the mean of its divisors is an integer number (4974147997).

Almost surely, 2^221001020100 is an apocalyptic number.

221001020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221001020100 is an abundant number, since it is smaller than the sum of its proper divisors (584810955414).

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

221001020100 is a wasteful number, since it uses less digits than its factorization.

221001020100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5011395 (or 5011378 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 221001020100 its reverse (1020100122), we get a palindrome (222021120222).

The spelling of 221001020100 in words is "two hundred twenty-one billion, one million, twenty thousand, one hundred".