220121553 has 4 divisors (see below), whose sum is σ = 293495408. Its totient is φ = 146747700.

The previous prime is 220121549. The next prime is 220121563. The reversal of 220121553 is 355121022.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 220121553 - 2² = 220121549 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (220121563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36686923 + ... + 36686928.

It is an arithmetic number, because the mean of its divisors is an integer number (73373852).

Almost surely, 2^220121553 is an apocalyptic number.

It is an amenable number.

220121553 is a deficient number, since it is larger than the sum of its proper divisors (73373855).

220121553 is an equidigital number, since it uses as much as digits as its factorization.

220121553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73373854.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 220121553 is about 14836.4939591536. The cubic root of 220121553 is about 603.7922338848.

Adding to 220121553 its reverse (355121022), we get a palindrome (575242575).

The spelling of 220121553 in words is "two hundred twenty million, one hundred twenty-one thousand, five hundred fifty-three".