1366669981 has 8 divisors (see below), whose sum is σ = 1439403200. Its totient is φ = 1294017120.

The previous prime is 1366669951. The next prime is 1366669991. The reversal of 1366669981 is 1899666631.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1366669981 - 2⁷ = 1366669853 is a prime.

It is a super-2 number, since 2×1366669981² = 3735573673933080722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1366669951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16561 + ... + 54841.

It is an arithmetic number, because the mean of its divisors is an integer number (179925400).

Almost surely, 2^1366669981 is an apocalyptic number.

It is an amenable number.

1366669981 is a deficient number, since it is larger than the sum of its proper divisors (72733219).

1366669981 is a wasteful number, since it uses less digits than its factorization.

1366669981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40179.

The product of its digits is 2519424, while the sum is 55.

The square root of 1366669981 is about 36968.4998478434. The cubic root of 1366669981 is about 1109.7399442180.

The spelling of 1366669981 in words is "one billion, three hundred sixty-six million, six hundred sixty-nine thousand, nine hundred eighty-one".