1281231565 has 8 divisors (see below), whose sum is σ = 1559132928. Its totient is φ = 1010548560.

The previous prime is 1281231547. The next prime is 1281231647. The reversal of 1281231565 is 5651321821.

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

It is not a de Polignac number, because 1281231565 - 2¹⁷ = 1281100493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1281231565.

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, 1804197 + ... + 1804906.

It is an arithmetic number, because the mean of its divisors is an integer number (194891616).

Almost surely, 2^1281231565 is an apocalyptic number.

It is an amenable number.

1281231565 is a deficient number, since it is larger than the sum of its proper divisors (277901363).

1281231565 is an equidigital number, since it uses as much as digits as its factorization.

1281231565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3609179.

The product of its digits is 14400, while the sum is 34.

The square root of 1281231565 is about 35794.2951460145. The cubic root of 1281231565 is about 1086.1151622779.

The spelling of 1281231565 in words is "one billion, two hundred eighty-one million, two hundred thirty-one thousand, five hundred sixty-five".