1285799512761 has 27 divisors (see below), whose sum is σ = 1863364151493. Its totient is φ = 854394329880.

The previous prime is 1285799512733. The next prime is 1285799512783. The reversal of 1285799512761 is 1672159975821.

The square root of 1285799512761 is 1133931.

It is a perfect power (a square), and thus also a powerful number.

1285799512761 is a `hidden beast` number, since 1 + 2 + 8 + 57 + 9 + 9 + 512 + 7 + 61 = 666.

It is not a de Polignac number, because 1285799512761 - 2⁵ = 1285799512729 is a prime.

It is a super-3 number, since 3×1285799512761³ (a number of 37 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1285799516761) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1860780426 + ... + 1860781116.

Almost surely, 2^{1285799512761} is an apocalyptic number.

1285799512761 is the 1133931-st square number.

1285799512761 is the 566966-th centered octagonal number.

It is an amenable number.

1285799512761 is a deficient number, since it is larger than the sum of its proper divisors (577564638732).

1285799512761 is an frugal number, since it uses more digits than its factorization.

1285799512761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2482 (or 1241 counting only the distinct ones).

The product of its digits is 19051200, while the sum is 63.

The spelling of 1285799512761 in words is "one trillion, two hundred eighty-five billion, seven hundred ninety-nine million, five hundred twelve thousand, seven hundred sixty-one".