21320182057 has 2 divisors, whose sum is σ = 21320182058. Its totient is φ = 21320182056.

The previous prime is 21320182049. The next prime is 21320182063. The reversal of 21320182057 is 75028102312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17537440041 + 3782742016 = 132429^2 + 61504^2 .

It is a cyclic number.

It is not a de Polignac number, because 21320182057 - 2³ = 21320182049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21320182067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660091028 + 10660091029.

It is an arithmetic number, because the mean of its divisors is an integer number (10660091029).

Almost surely, 2^21320182057 is an apocalyptic number.

It is an amenable number.

21320182057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21320182057 is an equidigital number, since it uses as much as digits as its factorization.

21320182057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6720, while the sum is 31.

Adding to 21320182057 its reverse (75028102312), we get a palindrome (96348284369).

The spelling of 21320182057 in words is "twenty-one billion, three hundred twenty million, one hundred eighty-two thousand, fifty-seven".