1280885781 has 16 divisors (see below), whose sum is σ = 1954601600. Its totient is φ = 730893888.

The previous prime is 1280885773. The next prime is 1280885789. The reversal of 1280885781 is 1875880821.

It is an interprime number because it is at equal distance from previous prime (1280885773) and next prime (1280885789).

It is not a de Polignac number, because 1280885781 - 2³ = 1280885773 is a prime.

It is a super-2 number, since 2×1280885781² = 3281336767935959922, 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 1280885781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1280885789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28126 + ... + 57903.

It is an arithmetic number, because the mean of its divisors is an integer number (122162600).

Almost surely, 2^1280885781 is an apocalyptic number.

It is an amenable number.

1280885781 is a deficient number, since it is larger than the sum of its proper divisors (673715819).

1280885781 is an equidigital number, since it uses as much as digits as its factorization.

1280885781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86748.

The product of its (nonzero) digits is 286720, while the sum is 48.

The square root of 1280885781 is about 35789.4646648982. The cubic root of 1280885781 is about 1086.0174450901.

It can be divided in two parts, 12808 and 85781, that added together give a palindrome (98589).

The spelling of 1280885781 in words is "one billion, two hundred eighty million, eight hundred eighty-five thousand, seven hundred eighty-one".