646242723450 has 144 divisors (see below), whose sum is σ = 1838903537016. Its totient is φ = 162147225600.

The previous prime is 646242723443. The next prime is 646242723479. The reversal of 646242723450 is 54327242646.

646242723450 is a `hidden beast` number, since 6 + 462 + 42 + 72 + 34 + 50 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 10046654289 + 636196069161 = 100233^2 + 797619^2 .

It is a super-2 number, since 2×646242723450² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 646242723396 and 646242723405.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 31760280 + ... + 31780620.

Almost surely, 2^646242723450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646242723450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (919451768508).

646242723450 is an abundant number, since it is smaller than the sum of its proper divisors (1192660813566).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646242723450 is a wasteful number, since it uses less digits than its factorization.

646242723450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24529 (or 24521 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 45.

The spelling of 646242723450 in words is "six hundred forty-six billion, two hundred forty-two million, seven hundred twenty-three thousand, four hundred fifty".