387681881 has 2 divisors, whose sum is σ = 387681882. Its totient is φ = 387681880.

The previous prime is 387681863. The next prime is 387681907. The reversal of 387681881 is 188186783.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 350288656 + 37393225 = 18716^2 + 6115^2 .

It is a cyclic number.

It is not a de Polignac number, because 387681881 - 2⁶ = 387681817 is a prime.

It is a super-2 number, since 2×387681881² = 300594481711396322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (387681181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193840940 + 193840941.

It is an arithmetic number, because the mean of its divisors is an integer number (193840941).

Almost surely, 2^387681881 is an apocalyptic number.

It is an amenable number.

387681881 is a deficient number, since it is larger than the sum of its proper divisors (1).

387681881 is an equidigital number, since it uses as much as digits as its factorization.

387681881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 516096, while the sum is 50.

The square root of 387681881 is about 19689.6389250794. The cubic root of 387681881 is about 729.1639148624.

The spelling of 387681881 in words is "three hundred eighty-seven million, six hundred eighty-one thousand, eight hundred eighty-one".