221001345 has 32 divisors (see below), whose sum is σ = 398442240. Its totient is φ = 116202240.

The previous prime is 221001337. The next prime is 221001349. The reversal of 221001345 is 543100122.

It is not a de Polignac number, because 221001345 - 2³ = 221001337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221001349) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1944 + ... + 21113.

It is an arithmetic number, because the mean of its divisors is an integer number (12451320).

Almost surely, 2^221001345 is an apocalyptic number.

It is an amenable number.

221001345 is a deficient number, since it is larger than the sum of its proper divisors (177440895).

221001345 is a wasteful number, since it uses less digits than its factorization.

221001345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23142 (or 23136 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 221001345 is about 14866.1139844951. The cubic root of 221001345 is about 604.5955861137.

Adding to 221001345 its reverse (543100122), we get a palindrome (764101467).

The spelling of 221001345 in words is "two hundred twenty-one million, one thousand, three hundred forty-five".