1366599881 has 2 divisors, whose sum is σ = 1366599882. Its totient is φ = 1366599880.

The previous prime is 1366599863. The next prime is 1366599887. The reversal of 1366599881 is 1889956631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1282785856 + 83814025 = 35816^2 + 9155^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1366599881 is a prime.

It is a super-2 number, since 2×1366599881² = 3735190469498428322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1366599887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 683299940 + 683299941.

It is an arithmetic number, because the mean of its divisors is an integer number (683299941).

Almost surely, 2^1366599881 is an apocalyptic number.

It is an amenable number.

1366599881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1366599881 is an equidigital number, since it uses as much as digits as its factorization.

1366599881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2799360, while the sum is 56.

The square root of 1366599881 is about 36967.5517312142. The cubic root of 1366599881 is about 1109.7209700932.

The spelling of 1366599881 in words is "one billion, three hundred sixty-six million, five hundred ninety-nine thousand, eight hundred eighty-one".