1657385813 has 2 divisors, whose sum is σ = 1657385814. Its totient is φ = 1657385812.

The previous prime is 1657385801. The next prime is 1657385831. The reversal of 1657385813 is 3185837561.

Together with next prime (1657385831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 920697649 + 736688164 = 30343^2 + 27142^2 .

It is an emirp because it is prime and its reverse (3185837561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1657385813 - 2¹⁴ = 1657369429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1657385893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 828692906 + 828692907.

It is an arithmetic number, because the mean of its divisors is an integer number (828692907).

Almost surely, 2^1657385813 is an apocalyptic number.

It is an amenable number.

1657385813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1657385813 is an equidigital number, since it uses as much as digits as its factorization.

1657385813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 604800, while the sum is 47.

The square root of 1657385813 is about 40711.0035862542. The cubic root of 1657385813 is about 1183.4262701236.

The spelling of 1657385813 in words is "one billion, six hundred fifty-seven million, three hundred eighty-five thousand, eight hundred thirteen".