220551021 has 6 divisors (see below), whose sum is σ = 318573710. Its totient is φ = 147034008.

The previous prime is 220551017. The next prime is 220551041. The reversal of 220551021 is 120155022.

It can be written as a sum of positive squares in only one way, i.e., 215649225 + 4901796 = 14685^2 + 2214^2 .

It is not a de Polignac number, because 220551021 - 2² = 220551017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 220550985 and 220551003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220551041) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12252826 + ... + 12252843.

Almost surely, 2^220551021 is an apocalyptic number.

It is an amenable number.

220551021 is a deficient number, since it is larger than the sum of its proper divisors (98022689).

220551021 is a wasteful number, since it uses less digits than its factorization.

220551021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24505675 (or 24505672 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 220551021 is about 14850.9602719824. The cubic root of 220551021 is about 604.1846549211.

The spelling of 220551021 in words is "two hundred twenty million, five hundred fifty-one thousand, twenty-one".