660279899869 has 4 divisors (see below), whose sum is σ = 667086909244. Its totient is φ = 653472890496.

The previous prime is 660279899857. The next prime is 660279899891. The reversal of 660279899869 is 968998972066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 524229577369 + 136050322500 = 724037^2 + 368850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660279899869 is a prime.

It is a super-2 number, since 2×660279899869² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660279899809) 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, 3403504542 + ... + 3403504735.

It is an arithmetic number, because the mean of its divisors is an integer number (166771727311).

Almost surely, 2^660279899869 is an apocalyptic number.

It is an amenable number.

660279899869 is a deficient number, since it is larger than the sum of its proper divisors (6807009375).

660279899869 is an equidigital number, since it uses as much as digits as its factorization.

660279899869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6807009374.

The product of its (nonzero) digits is 1269789696, while the sum is 79.

The spelling of 660279899869 in words is "six hundred sixty billion, two hundred seventy-nine million, eight hundred ninety-nine thousand, eight hundred sixty-nine".