1381066566 has 64 divisors (see below), whose sum is σ = 3180038400. Its totient is φ = 395452800.

The previous prime is 1381066543. The next prime is 1381066571. The reversal of 1381066566 is 6656601831.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 576900 + ... + 579288.

It is an arithmetic number, because the mean of its divisors is an integer number (49688100).

Almost surely, 2^1381066566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1381066566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1590019200).

1381066566 is an abundant number, since it is smaller than the sum of its proper divisors (1798971834).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1381066566 is a wasteful number, since it uses less digits than its factorization.

1381066566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2885.

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 1381066566 is about 37162.7039651315. The cubic root of 1381066566 is about 1113.6230305162.

The spelling of 1381066566 in words is "one billion, three hundred eighty-one million, sixty-six thousand, five hundred sixty-six".