1285645721679 has 48 divisors (see below), whose sum is σ = 2171080963584. Its totient is φ = 725158526400.

The previous prime is 1285645721669. The next prime is 1285645721707. The reversal of 1285645721679 is 9761275465821.

It is a happy number.

1285645721679 is a `hidden beast` number, since 1 + 2 + 8 + 56 + 4 + 572 + 1 + 6 + 7 + 9 = 666.

It is not a de Polignac number, because 1285645721679 - 2⁹ = 1285645721167 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285645721669) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7545787 + ... + 7714284.

It is an arithmetic number, because the mean of its divisors is an integer number (45230853408).

Almost surely, 2^{1285645721679} is an apocalyptic number.

1285645721679 is a deficient number, since it is larger than the sum of its proper divisors (885435241905).

1285645721679 is a wasteful number, since it uses less digits than its factorization.

1285645721679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15260148 (or 15260145 counting only the distinct ones).

The product of its digits is 50803200, while the sum is 63.

The spelling of 1285645721679 in words is "one trillion, two hundred eighty-five billion, six hundred forty-five million, seven hundred twenty-one thousand, six hundred seventy-nine".