221020538 has 16 divisors (see below), whose sum is σ = 337970880. Its totient is φ = 108378336.

The previous prime is 221020537. The next prime is 221020543. The reversal of 221020538 is 835020122.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221020531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27683 + ... + 34761.

It is an arithmetic number, because the mean of its divisors is an integer number (21123180).

Almost surely, 2^221020538 is an apocalyptic number.

221020538 is a deficient number, since it is larger than the sum of its proper divisors (116950342).

221020538 is a wasteful number, since it uses less digits than its factorization.

221020538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7381.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 221020538 is about 14866.7594989628. The cubic root of 221020538 is about 604.6130877677.

The spelling of 221020538 in words is "two hundred twenty-one million, twenty thousand, five hundred thirty-eight".