387991169 has 2 divisors, whose sum is σ = 387991170. Its totient is φ = 387991168.

The previous prime is 387991147. The next prime is 387991183. The reversal of 387991169 is 961199783.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209902144 + 178089025 = 14488^2 + 13345^2 .

It is a cyclic number.

It is not a de Polignac number, because 387991169 - 2¹⁶ = 387925633 is a prime.

It is a super-2 number, since 2×387991169² = 301074294443973122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 387991169.

It is not a weakly prime, because it can be changed into another prime (387991189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193995584 + 193995585.

It is an arithmetic number, because the mean of its divisors is an integer number (193995585).

Almost surely, 2^387991169 is an apocalyptic number.

It is an amenable number.

387991169 is a deficient number, since it is larger than the sum of its proper divisors (1).

387991169 is an equidigital number, since it uses as much as digits as its factorization.

387991169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 53.

The square root of 387991169 is about 19697.4914392671. The cubic root of 387991169 is about 729.3577694234.

The spelling of 387991169 in words is "three hundred eighty-seven million, nine hundred ninety-one thousand, one hundred sixty-nine".