221478020 has 12 divisors (see below), whose sum is σ = 465103884. Its totient is φ = 88591200.

The previous prime is 221477987. The next prime is 221478067. The reversal of 221478020 is 20874122.

221478020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 78818884 + 142659136 = 8878^2 + 11944^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5536931 + ... + 5536970.

It is an arithmetic number, because the mean of its divisors is an integer number (38758657).

Almost surely, 2^221478020 is an apocalyptic number.

221478020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221478020 is an abundant number, since it is smaller than the sum of its proper divisors (243625864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221478020 is a wasteful number, since it uses less digits than its factorization.

221478020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11073910 (or 11073908 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 221478020 is about 14882.1376152756. The cubic root of 221478020 is about 605.0299554869.

The spelling of 221478020 in words is "two hundred twenty-one million, four hundred seventy-eight thousand, twenty".