1380640581 has 24 divisors (see below), whose sum is σ = 2017345824. Its totient is φ = 909810720.

The previous prime is 1380640579. The next prime is 1380640589. The reversal of 1380640581 is 1850460831.

1380640581 is a `hidden beast` number, since 1 + 3 + 8 + 0 + 640 + 5 + 8 + 1 = 666.

It is not a de Polignac number, because 1380640581 - 2¹ = 1380640579 is a prime.

It is a super-2 number, since 2×1380640581² = 3812336827808035122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1380640589) 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, 525451 + ... + 528071.

It is an arithmetic number, because the mean of its divisors is an integer number (84056076).

Almost surely, 2^1380640581 is an apocalyptic number.

It is an amenable number.

1380640581 is a deficient number, since it is larger than the sum of its proper divisors (636705243).

1380640581 is a wasteful number, since it uses less digits than its factorization.

1380640581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3281 (or 3278 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 1380640581 is about 37156.9721721240. The cubic root of 1380640581 is about 1113.5085210733.

The spelling of 1380640581 in words is "one billion, three hundred eighty million, six hundred forty thousand, five hundred eighty-one".