221031345 has 16 divisors (see below), whose sum is σ = 354477312. Its totient is φ = 117607680.

The previous prime is 221031341. The next prime is 221031373. The reversal of 221031345 is 543130122.

It is not a de Polignac number, because 221031345 - 2² = 221031341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221031341) 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, 10521 + ... + 23510.

It is an arithmetic number, because the mean of its divisors is an integer number (22154832).

Almost surely, 2^221031345 is an apocalyptic number.

It is an amenable number.

221031345 is a deficient number, since it is larger than the sum of its proper divisors (133445967).

221031345 is a wasteful number, since it uses less digits than its factorization.

221031345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34472.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 221031345 is about 14867.1229563759. The cubic root of 221031345 is about 604.6229419758.

Adding to 221031345 its reverse (543130122), we get a palindrome (764161467).

The spelling of 221031345 in words is "two hundred twenty-one million, thirty-one thousand, three hundred forty-five".