38766661561 has 2 divisors, whose sum is σ = 38766661562. Its totient is φ = 38766661560.

The previous prime is 38766661559. The next prime is 38766661639. The reversal of 38766661561 is 16516666783.

It is a happy number.

38766661561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35556759225 + 3209902336 = 188565^2 + 56656^2 .

It is a cyclic number.

It is not a de Polignac number, because 38766661561 - 2¹ = 38766661559 is a prime.

It is a super-2 number, since 2×38766661561² (a number of 22 digits) contains 22 as substring.

Together with 38766661559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (38766661861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19383330780 + 19383330781.

It is an arithmetic number, because the mean of its divisors is an integer number (19383330781).

Almost surely, 2^38766661561 is an apocalyptic number.

It is an amenable number.

38766661561 is a deficient number, since it is larger than the sum of its proper divisors (1).

38766661561 is an equidigital number, since it uses as much as digits as its factorization.

38766661561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6531840, while the sum is 55.

The spelling of 38766661561 in words is "thirty-eight billion, seven hundred sixty-six million, six hundred sixty-one thousand, five hundred sixty-one".