1657172213 has 2 divisors, whose sum is σ = 1657172214. Its totient is φ = 1657172212.

The previous prime is 1657172183. The next prime is 1657172219. The reversal of 1657172213 is 3122717561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 935014084 + 722158129 = 30578^2 + 26873^2 .

It is an emirp because it is prime and its reverse (3122717561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1657172213 - 2¹⁶ = 1657106677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1657172219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 828586106 + 828586107.

It is an arithmetic number, because the mean of its divisors is an integer number (828586107).

Almost surely, 2^1657172213 is an apocalyptic number.

It is an amenable number.

1657172213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1657172213 is an equidigital number, since it uses as much as digits as its factorization.

1657172213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17640, while the sum is 35.

The square root of 1657172213 is about 40708.3801323511. The cubic root of 1657172213 is about 1183.3754288712.

Adding to 1657172213 its reverse (3122717561), we get a palindrome (4779889774).

The spelling of 1657172213 in words is "one billion, six hundred fifty-seven million, one hundred seventy-two thousand, two hundred thirteen".