1321257785 has 16 divisors (see below), whose sum is σ = 1595244672. Its totient is φ = 1050537600.

The previous prime is 1321257767. The next prime is 1321257787. The reversal of 1321257785 is 5877521231.

It is not a de Polignac number, because 1321257785 - 2²⁶ = 1254148921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321257787) 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, 683270 + ... + 685200.

It is an arithmetic number, because the mean of its divisors is an integer number (99702792).

Almost surely, 2^1321257785 is an apocalyptic number.

It is an amenable number.

1321257785 is a deficient number, since it is larger than the sum of its proper divisors (273986887).

1321257785 is a wasteful number, since it uses less digits than its factorization.

1321257785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2704.

The product of its digits is 117600, while the sum is 41.

The square root of 1321257785 is about 36349.1098240383. The cubic root of 1321257785 is about 1097.3096194453.

The spelling of 1321257785 in words is "one billion, three hundred twenty-one million, two hundred fifty-seven thousand, seven hundred eighty-five".