1387788161 has 2 divisors, whose sum is σ = 1387788162. Its totient is φ = 1387788160.

The previous prime is 1387788121. The next prime is 1387788169. The reversal of 1387788161 is 1618877831.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1198890625 + 188897536 = 34625^2 + 13744^2 .

It is a cyclic number.

It is not a de Polignac number, because 1387788161 - 2⁶ = 1387788097 is a prime.

It is not a weakly prime, because it can be changed into another prime (1387788169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 693894080 + 693894081.

It is an arithmetic number, because the mean of its divisors is an integer number (693894081).

Almost surely, 2^1387788161 is an apocalyptic number.

It is an amenable number.

1387788161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1387788161 is an equidigital number, since it uses as much as digits as its factorization.

1387788161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 451584, while the sum is 50.

The square root of 1387788161 is about 37253.0288835686. The cubic root of 1387788161 is about 1115.4267601645.

The spelling of 1387788161 in words is "one billion, three hundred eighty-seven million, seven hundred eighty-eight thousand, one hundred sixty-one".