221020280 has 32 divisors (see below), whose sum is σ = 535550400. Its totient is φ = 81607296.

The previous prime is 221020279. The next prime is 221020321. The reversal of 221020280 is 82020122.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212000 + ... + 213039.

It is an arithmetic number, because the mean of its divisors is an integer number (16735950).

Almost surely, 2^221020280 is an apocalyptic number.

221020280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221020280 is an abundant number, since it is smaller than the sum of its proper divisors (314530120).

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

221020280 is a wasteful number, since it uses less digits than its factorization.

221020280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425063 (or 425059 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 221020280 is about 14866.7508218844. The cubic root of 221020280 is about 604.6128525101.

The spelling of 221020280 in words is "two hundred twenty-one million, twenty thousand, two hundred eighty".