221078145 has 16 divisors (see below), whose sum is σ = 363286080. Its totient is φ = 114721344.

The previous prime is 221078141. The next prime is 221078147. The reversal of 221078145 is 541870122.

It is not a de Polignac number, because 221078145 - 2² = 221078141 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221078141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 198615 + ... + 199724.

It is an arithmetic number, because the mean of its divisors is an integer number (22705380).

Almost surely, 2^221078145 is an apocalyptic number.

It is an amenable number.

221078145 is a deficient number, since it is larger than the sum of its proper divisors (142207935).

221078145 is a wasteful number, since it uses less digits than its factorization.

221078145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398384.

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 221078145 is about 14868.6968157939. The cubic root of 221078145 is about 604.6656121784.

The spelling of 221078145 in words is "two hundred twenty-one million, seventy-eight thousand, one hundred forty-five".