1263888889 has 2 divisors, whose sum is σ = 1263888890. Its totient is φ = 1263888888.

The previous prime is 1263888881. The next prime is 1263888907. The reversal of 1263888889 is 9888883621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1153281600 + 110607289 = 33960^2 + 10517^2 .

It is a cyclic number.

It is not a de Polignac number, because 1263888889 - 2³ = 1263888881 is a prime.

It is not a weakly prime, because it can be changed into another prime (1263888881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631944444 + 631944445.

It is an arithmetic number, because the mean of its divisors is an integer number (631944445).

Almost surely, 2^1263888889 is an apocalyptic number.

It is an amenable number.

1263888889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263888889 is an equidigital number, since it uses as much as digits as its factorization.

1263888889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10616832, while the sum is 61.

The square root of 1263888889 is about 35551.2150143986. The cubic root of 1263888889 is about 1081.1923528177.

The spelling of 1263888889 in words is "one billion, two hundred sixty-three million, eight hundred eighty-eight thousand, eight hundred eighty-nine".