220101021 has 12 divisors (see below), whose sum is σ = 363341472. Its totient is φ = 125771976.

The previous prime is 220101017. The next prime is 220101041. The reversal of 220101021 is 120101022.

It is not a de Polignac number, because 220101021 - 2² = 220101017 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 220100994 and 220101012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220101041) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 1746771 + ... + 1746896.

It is an arithmetic number, because the mean of its divisors is an integer number (30278456).

Almost surely, 2^220101021 is an apocalyptic number.

220101021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

220101021 is a deficient number, since it is larger than the sum of its proper divisors (143240451).

220101021 is a wasteful number, since it uses less digits than its factorization.

220101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3493680 (or 3493677 counting only the distinct ones).

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

The square root of 220101021 is about 14835.8020005661. The cubic root of 220101021 is about 603.7734602460.

Adding to 220101021 its reverse (120101022), we get a palindrome (340202043).

Subtracting from 220101021 its reverse (120101022), we obtain a palindrome (99999999).

The spelling of 220101021 in words is "two hundred twenty million, one hundred one thousand, twenty-one".