387889891 has 2 divisors, whose sum is σ = 387889892. Its totient is φ = 387889890.

The previous prime is 387889847. The next prime is 387889903. The reversal of 387889891 is 198988783.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 387889891 - 2⁹ = 387889379 is a prime.

It is not a weakly prime, because it can be changed into another prime (387889841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193944945 + 193944946.

It is an arithmetic number, because the mean of its divisors is an integer number (193944946).

Almost surely, 2^387889891 is an apocalyptic number.

387889891 is a deficient number, since it is larger than the sum of its proper divisors (1).

387889891 is an equidigital number, since it uses as much as digits as its factorization.

387889891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6967296, while the sum is 61.

The square root of 387889891 is about 19694.9204364983. The cubic root of 387889891 is about 729.2943020645.

The spelling of 387889891 in words is "three hundred eighty-seven million, eight hundred eighty-nine thousand, eight hundred ninety-one".