378261581 has 2 divisors, whose sum is σ = 378261582. Its totient is φ = 378261580.

The previous prime is 378261571. The next prime is 378261589. The reversal of 378261581 is 185162873.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 304816681 + 73444900 = 17459^2 + 8570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-378261581 is a prime.

It is a super-2 number, since 2×378261581² = 286163647321239122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (378261589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 189130790 + 189130791.

It is an arithmetic number, because the mean of its divisors is an integer number (189130791).

Almost surely, 2^378261581 is an apocalyptic number.

It is an amenable number.

378261581 is a deficient number, since it is larger than the sum of its proper divisors (1).

378261581 is an equidigital number, since it uses as much as digits as its factorization.

378261581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 41.

The square root of 378261581 is about 19448.9480692401. The cubic root of 378261581 is about 723.2094258276.

The spelling of 378261581 in words is "three hundred seventy-eight million, two hundred sixty-one thousand, five hundred eighty-one".