378149561 has 2 divisors, whose sum is σ = 378149562. Its totient is φ = 378149560.

The previous prime is 378149549. The next prime is 378149567. The reversal of 378149561 is 165941873.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 377719225 + 430336 = 19435^2 + 656^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-378149561 is a prime.

It is not a weakly prime, because it can be changed into another prime (378149567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 189074780 + 189074781.

It is an arithmetic number, because the mean of its divisors is an integer number (189074781).

Almost surely, 2^378149561 is an apocalyptic number.

It is an amenable number.

378149561 is a deficient number, since it is larger than the sum of its proper divisors (1).

378149561 is an equidigital number, since it uses as much as digits as its factorization.

378149561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 44.

The square root of 378149561 is about 19446.0680087261. The cubic root of 378149561 is about 723.1380273364.

The spelling of 378149561 in words is "three hundred seventy-eight million, one hundred forty-nine thousand, five hundred sixty-one".