1881378061 has 2 divisors, whose sum is σ = 1881378062. Its totient is φ = 1881378060.

The previous prime is 1881378053. The next prime is 1881378067. The reversal of 1881378061 is 1608731881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1877575561 + 3802500 = 43331^2 + 1950^2 .

It is a cyclic number.

It is not a de Polignac number, because 1881378061 - 2³ = 1881378053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1881377999 and 1881378017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1881378067) 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, 940689030 + 940689031.

It is an arithmetic number, because the mean of its divisors is an integer number (940689031).

Almost surely, 2^1881378061 is an apocalyptic number.

It is an amenable number.

1881378061 is a deficient number, since it is larger than the sum of its proper divisors (1).

1881378061 is an equidigital number, since it uses as much as digits as its factorization.

1881378061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 1881378061 is about 43374.8551697870. The cubic root of 1881378061 is about 1234.5026459813.

The spelling of 1881378061 in words is "one billion, eight hundred eighty-one million, three hundred seventy-eight thousand, sixty-one".