220521116021 has 4 divisors (see below), whose sum is σ = 225649514112. Its totient is φ = 215392717932.

The previous prime is 220521116017. The next prime is 220521116077. The reversal of 220521116021 is 120611125022.

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, and also an emirpimes, since its reverse is a distinct semiprime: 120611125022 = 2 ⋅60305562511.

It is a cyclic number.

It is not a de Polignac number, because 220521116021 - 2² = 220521116017 is a prime.

It is a super-2 number, since 2×220521116021² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220521110021) 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, 2564198981 + ... + 2564199066.

It is an arithmetic number, because the mean of its divisors is an integer number (56412378528).

Almost surely, 2^220521116021 is an apocalyptic number.

It is an amenable number.

220521116021 is a deficient number, since it is larger than the sum of its proper divisors (5128398091).

220521116021 is an equidigital number, since it uses as much as digits as its factorization.

220521116021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5128398090.

The product of its (nonzero) digits is 480, while the sum is 23.

Subtracting from 220521116021 its reverse (120611125022), we obtain a palindrome (99909990999).

The spelling of 220521116021 in words is "two hundred twenty billion, five hundred twenty-one million, one hundred sixteen thousand, twenty-one".