20381621206477 has 2 divisors, whose sum is σ = 20381621206478. Its totient is φ = 20381621206476.

The previous prime is 20381621206459. The next prime is 20381621206501. The reversal of 20381621206477 is 77460212618302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17455232778916 + 2926388427561 = 4177946^2 + 1710669^2 .

It is a cyclic number.

It is not a de Polignac number, because 20381621206477 - 2¹¹ = 20381621204429 is a prime.

It is a super-2 number, since 2×20381621206477² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20381621206477.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20381621206417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10190810603238 + 10190810603239.

It is an arithmetic number, because the mean of its divisors is an integer number (10190810603239).

Almost surely, 2^{20381621206477} is an apocalyptic number.

It is an amenable number.

20381621206477 is a deficient number, since it is larger than the sum of its proper divisors (1).

20381621206477 is an equidigital number, since it uses as much as digits as its factorization.

20381621206477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1354752, while the sum is 49.

The spelling of 20381621206477 in words is "twenty trillion, three hundred eighty-one billion, six hundred twenty-one million, two hundred six thousand, four hundred seventy-seven".