257173224221 has 4 divisors (see below), whose sum is σ = 260062811100. Its totient is φ = 254283637344.

The previous prime is 257173224211. The next prime is 257173224227. The reversal of 257173224221 is 122422371752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 81046118596 + 176127105625 = 284686^2 + 419675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257173224221 is a prime.

It is a super-2 number, since 2×257173224221² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257173224227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1444793306 + ... + 1444793483.

It is an arithmetic number, because the mean of its divisors is an integer number (65015702775).

Almost surely, 2^257173224221 is an apocalyptic number.

It is an amenable number.

257173224221 is a deficient number, since it is larger than the sum of its proper divisors (2889586879).

257173224221 is an equidigital number, since it uses as much as digits as its factorization.

257173224221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2889586878.

The product of its digits is 94080, while the sum is 38.

Adding to 257173224221 its reverse (122422371752), we get a palindrome (379595595973).

The spelling of 257173224221 in words is "two hundred fifty-seven billion, one hundred seventy-three million, two hundred twenty-four thousand, two hundred twenty-one".