7644665642 has 8 divisors (see below), whose sum is σ = 11585215236. Its totient is φ = 3782927232.

The previous prime is 7644665617. The next prime is 7644665671. The reversal of 7644665642 is 2465664467.

It can be written as a sum of positive squares in 2 ways, for example, as 7346032681 + 298632961 = 85709^2 + 17281^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19702553 + ... + 19702940.

Almost surely, 2^7644665642 is an apocalyptic number.

7644665642 is a deficient number, since it is larger than the sum of its proper divisors (3940549594).

7644665642 is a wasteful number, since it uses less digits than its factorization.

7644665642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39405592.

The product of its digits is 5806080, while the sum is 50.

The square root of 7644665642 is about 87433.7786098714. The cubic root of 7644665642 is about 1969.9392426313.

The spelling of 7644665642 in words is "seven billion, six hundred forty-four million, six hundred sixty-five thousand, six hundred forty-two".