642723851650 has 12 divisors (see below), whose sum is σ = 1195466364162. Its totient is φ = 257089540640.

The previous prime is 642723851617. The next prime is 642723851689. The reversal of 642723851650 is 56158327246.

It can be written as a sum of positive squares in 3 ways, for example, as 312663260569 + 330060591081 = 559163^2 + 574509^2 .

It is a super-4 number, since 4×642723851650⁴ (a number of 48 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 642723851594 and 642723851603.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6427238467 + ... + 6427238566.

Almost surely, 2^642723851650 is an apocalyptic number.

642723851650 is a deficient number, since it is larger than the sum of its proper divisors (552742512512).

642723851650 is a wasteful number, since it uses less digits than its factorization.

642723851650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12854477045 (or 12854477040 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 49.

The spelling of 642723851650 in words is "six hundred forty-two billion, seven hundred twenty-three million, eight hundred fifty-one thousand, six hundred fifty".