221157028 has 12 divisors (see below), whose sum is σ = 387797760. Its totient is φ = 110357672.

The previous prime is 221157011. The next prime is 221157031. The reversal of 221157028 is 820751122.

221157028 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 221156987 and 221157005.

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, 52948 + ... + 56971.

It is an arithmetic number, because the mean of its divisors is an integer number (32316480).

Almost surely, 2^221157028 is an apocalyptic number.

It is an amenable number.

221157028 is a deficient number, since it is larger than the sum of its proper divisors (166640732).

221157028 is a wasteful number, since it uses less digits than its factorization.

221157028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110426 (or 110424 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 221157028 is about 14871.3492326688. The cubic root of 221157028 is about 604.7375206365.

The spelling of 221157028 in words is "two hundred twenty-one million, one hundred fifty-seven thousand, twenty-eight".