646277957869 has 4 divisors (see below), whose sum is σ = 646279756380. Its totient is φ = 646276159360.

The previous prime is 646277957863. The next prime is 646277957873. The reversal of 646277957869 is 968759772646.

646277957869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 460990755369 + 185287202500 = 678963^2 + 430450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646277957869 is a prime.

It is a super-2 number, since 2×646277957869² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646277957795 and 646277957804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646277957863) 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, 154822 + ... + 1147399.

It is an arithmetic number, because the mean of its divisors is an integer number (161569939095).

Almost surely, 2^646277957869 is an apocalyptic number.

It is an amenable number.

646277957869 is a deficient number, since it is larger than the sum of its proper divisors (1798511).

646277957869 is a wasteful number, since it uses less digits than its factorization.

646277957869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1798510.

The product of its digits is 1920360960, while the sum is 76.

The spelling of 646277957869 in words is "six hundred forty-six billion, two hundred seventy-seven million, nine hundred fifty-seven thousand, eight hundred sixty-nine".