1285120309 has 36 divisors (see below), whose sum is σ = 1523116000. Its totient is φ = 1080462240.

The previous prime is 1285120303. The next prime is 1285120327. The reversal of 1285120309 is 9030215821.

It is not a de Polignac number, because 1285120309 - 2¹⁵ = 1285087541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285120303) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6457792 + ... + 6457990.

Almost surely, 2^1285120309 is an apocalyptic number.

1285120309 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1285120309 is a deficient number, since it is larger than the sum of its proper divisors (237995691).

1285120309 is a wasteful number, since it uses less digits than its factorization.

1285120309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1285120309 is about 35848.5747136480. The cubic root of 1285120309 is about 1087.2128971971.

The spelling of 1285120309 in words is "one billion, two hundred eighty-five million, one hundred twenty thousand, three hundred nine".