378556781 has 2 divisors, whose sum is σ = 378556782. Its totient is φ = 378556780.

The previous prime is 378556751. The next prime is 378556811. The reversal of 378556781 is 187655873.

It is a balanced prime because it is at equal distance from previous prime (378556751) and next prime (378556811).

It can be written as a sum of positive squares in only one way, i.e., 363664900 + 14891881 = 19070^2 + 3859^2 .

It is a cyclic number.

It is not a de Polignac number, because 378556781 - 2¹⁰ = 378555757 is a prime.

It is a super-2 number, since 2×378556781² = 286610472882163922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (378556751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 189278390 + 189278391.

It is an arithmetic number, because the mean of its divisors is an integer number (189278391).

Almost surely, 2^378556781 is an apocalyptic number.

It is an amenable number.

378556781 is a deficient number, since it is larger than the sum of its proper divisors (1).

378556781 is an equidigital number, since it uses as much as digits as its factorization.

378556781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1411200, while the sum is 50.

The square root of 378556781 is about 19456.5356885546. The cubic root of 378556781 is about 723.3975107580.

The spelling of 378556781 in words is "three hundred seventy-eight million, five hundred fifty-six thousand, seven hundred eighty-one".