38778781 has 2 divisors, whose sum is σ = 38778782. Its totient is φ = 38778780.

The previous prime is 38778769. The next prime is 38778793. The reversal of 38778781 is 18787783.

It is a balanced prime because it is at equal distance from previous prime (38778769) and next prime (38778793).

It can be written as a sum of positive squares in only one way, i.e., 31304025 + 7474756 = 5595^2 + 2734^2 .

It is a cyclic number.

It is not a de Polignac number, because 38778781 - 2⁹ = 38778269 is a prime.

It is a super-2 number, since 2×38778781² = 3007587711691922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38773781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19389390 + 19389391.

It is an arithmetic number, because the mean of its divisors is an integer number (19389391).

Almost surely, 2^38778781 is an apocalyptic number.

It is an amenable number.

38778781 is a deficient number, since it is larger than the sum of its proper divisors (1).

38778781 is an equidigital number, since it uses as much as digits as its factorization.

38778781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 526848, while the sum is 49.

The square root of 38778781 is about 6227.2611154504. The cubic root of 38778781 is about 338.4787311899.

The spelling of 38778781 in words is "thirty-eight million, seven hundred seventy-eight thousand, seven hundred eighty-one".