220040021 has 2 divisors, whose sum is σ = 220040022. Its totient is φ = 220040020.

The previous prime is 220039979. The next prime is 220040039. The reversal of 220040021 is 120040022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219336100 + 703921 = 14810^2 + 839^2 .

It is a cyclic number.

It is not a de Polignac number, because 220040021 - 2⁶ = 220039957 is a prime.

It is a super-2 number, since 2×220040021² = 96835221683360882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 220039984 and 220040011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220040321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110020010 + 110020011.

It is an arithmetic number, because the mean of its divisors is an integer number (110020011).

Almost surely, 2^220040021 is an apocalyptic number.

It is an amenable number.

220040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

220040021 is an equidigital number, since it uses as much as digits as its factorization.

220040021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 220040021 is about 14833.7460204764. The cubic root of 220040021 is about 603.7176774001.

Adding to 220040021 its reverse (120040022), we get a palindrome (340080043).

Subtracting from 220040021 its reverse (120040022), we obtain a palindrome (99999999).

The spelling of 220040021 in words is "two hundred twenty million, forty thousand, twenty-one".