20645000381 has 2 divisors, whose sum is σ = 20645000382. Its totient is φ = 20645000380.

The previous prime is 20645000347. The next prime is 20645000393. The reversal of 20645000381 is 18300054602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15102197881 + 5542802500 = 122891^2 + 74450^2 .

It is a cyclic number.

It is not a de Polignac number, because 20645000381 - 2¹⁰ = 20644999357 is a prime.

It is a super-2 number, since 2×20645000381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20645002381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322500190 + 10322500191.

It is an arithmetic number, because the mean of its divisors is an integer number (10322500191).

Almost surely, 2^20645000381 is an apocalyptic number.

It is an amenable number.

20645000381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645000381 is an equidigital number, since it uses as much as digits as its factorization.

20645000381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 29.

Adding to 20645000381 its reverse (18300054602), we get a palindrome (38945054983).

The spelling of 20645000381 in words is "twenty billion, six hundred forty-five million, three hundred eighty-one", and thus it is an aban number.