1381537565 has 8 divisors (see below), whose sum is σ = 1658365368. Its totient is φ = 1104883200.

The previous prime is 1381537559. The next prime is 1381537601. The reversal of 1381537565 is 5657351831.

It can be written as a sum of positive squares in 4 ways, for example, as 531348601 + 850188964 = 23051^2 + 29158^2 .

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

It is not a de Polignac number, because 1381537565 - 2⁶ = 1381537501 is a prime.

It is a super-2 number, since 2×1381537565² = 3817292087012258450, which contains 22 as substring.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 25136 + ... + 58265.

It is an arithmetic number, because the mean of its divisors is an integer number (207295671).

Almost surely, 2^1381537565 is an apocalyptic number.

It is an amenable number.

1381537565 is a deficient number, since it is larger than the sum of its proper divisors (276827803).

1381537565 is an equidigital number, since it uses as much as digits as its factorization.

1381537565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86719.

The product of its digits is 378000, while the sum is 44.

The square root of 1381537565 is about 37169.0404099971. The cubic root of 1381537565 is about 1113.7496128092.

The spelling of 1381537565 in words is "one billion, three hundred eighty-one million, five hundred thirty-seven thousand, five hundred sixty-five".