1386661881 has 24 divisors (see below), whose sum is σ = 2108496096. Its totient is φ = 803851840.

The previous prime is 1386661873. The next prime is 1386661891. The reversal of 1386661881 is 1881666831.

It is not a de Polignac number, because 1386661881 - 2³ = 1386661873 is a prime.

It is a super-2 number, since 2×1386661881² = 3845662344436916322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1386661881.

It is not an unprimeable number, because it can be changed into a prime (1386661811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22260 + ... + 57173.

It is an arithmetic number, because the mean of its divisors is an integer number (87854004).

Almost surely, 2^1386661881 is an apocalyptic number.

1386661881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1386661881 is a deficient number, since it is larger than the sum of its proper divisors (721834215).

1386661881 is a wasteful number, since it uses less digits than its factorization.

1386661881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79493 (or 79470 counting only the distinct ones).

The product of its digits is 331776, while the sum is 48.

The square root of 1386661881 is about 37237.9091921123. The cubic root of 1386661881 is about 1115.1249314725.

The spelling of 1386661881 in words is "one billion, three hundred eighty-six million, six hundred sixty-one thousand, eight hundred eighty-one".