1391869889 has 2 divisors, whose sum is σ = 1391869890. Its totient is φ = 1391869888.

The previous prime is 1391869847. The next prime is 1391869901. The reversal of 1391869889 is 9889681931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1280208400 + 111661489 = 35780^2 + 10567^2 .

It is a cyclic number.

It is not a de Polignac number, because 1391869889 - 2¹² = 1391865793 is a prime.

It is not a weakly prime, because it can be changed into another prime (1391862889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695934944 + 695934945.

It is an arithmetic number, because the mean of its divisors is an integer number (695934945).

Almost surely, 2^1391869889 is an apocalyptic number.

It is an amenable number.

1391869889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391869889 is an equidigital number, since it uses as much as digits as its factorization.

1391869889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6718464, while the sum is 62.

The square root of 1391869889 is about 37307.7725011826. The cubic root of 1391869889 is about 1116.5192449427.

The spelling of 1391869889 in words is "one billion, three hundred ninety-one million, eight hundred sixty-nine thousand, eight hundred eighty-nine".