1285988917 has 4 divisors (see below), whose sum is σ = 1315895680. Its totient is φ = 1256082156.

The previous prime is 1285988881. The next prime is 1285988947. The reversal of 1285988917 is 7198895821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1285988917 - 2²⁷ = 1151771189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285988947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14953317 + ... + 14953402.

It is an arithmetic number, because the mean of its divisors is an integer number (328973920).

Almost surely, 2^1285988917 is an apocalyptic number.

It is an amenable number.

1285988917 is a deficient number, since it is larger than the sum of its proper divisors (29906763).

1285988917 is an equidigital number, since it uses as much as digits as its factorization.

1285988917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29906762.

The product of its digits is 2903040, while the sum is 58.

The square root of 1285988917 is about 35860.6876258669. The cubic root of 1285988917 is about 1087.4577897388.

The spelling of 1285988917 in words is "one billion, two hundred eighty-five million, nine hundred eighty-eight thousand, nine hundred seventeen".