30920785657 has 2 divisors, whose sum is σ = 30920785658. Its totient is φ = 30920785656.

The previous prime is 30920785639. The next prime is 30920785673. The reversal of 30920785657 is 75658702903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25647702201 + 5273083456 = 160149^2 + 72616^2 .

It is a cyclic number.

It is not a de Polignac number, because 30920785657 - 2¹¹ = 30920783609 is a prime.

It is a super-2 number, since 2×30920785657² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (30920785627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15460392828 + 15460392829.

It is an arithmetic number, because the mean of its divisors is an integer number (15460392829).

Almost surely, 2^30920785657 is an apocalyptic number.

It is an amenable number.

30920785657 is a deficient number, since it is larger than the sum of its proper divisors (1).

30920785657 is an equidigital number, since it uses as much as digits as its factorization.

30920785657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3175200, while the sum is 52.

The spelling of 30920785657 in words is "thirty billion, nine hundred twenty million, seven hundred eighty-five thousand, six hundred fifty-seven".