20381657788837 has 2 divisors, whose sum is σ = 20381657788838. Its totient is φ = 20381657788836.

The previous prime is 20381657788717. The next prime is 20381657788847. The reversal of 20381657788837 is 73888775618302.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16528704933601 + 3852952855236 = 4065551^2 + 1962894^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20381657788837 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20381657788837.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20381657788847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10190828894418 + 10190828894419.

It is an arithmetic number, because the mean of its divisors is an integer number (10190828894419).

Almost surely, 2^{20381657788837} is an apocalyptic number.

It is an amenable number.

20381657788837 is a deficient number, since it is larger than the sum of its proper divisors (1).

20381657788837 is an equidigital number, since it uses as much as digits as its factorization.

20381657788837 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 758661120, while the sum is 73.

The spelling of 20381657788837 in words is "twenty trillion, three hundred eighty-one billion, six hundred fifty-seven million, seven hundred eighty-eight thousand, eight hundred thirty-seven".