6640451642 has 16 divisors (see below), whose sum is σ = 11159875872. Its totient is φ = 2936808720.

The previous prime is 6640451633. The next prime is 6640451659. The reversal of 6640451642 is 2461540466.

It is a junction number, because it is equal to n+sod(n) for n = 6640451596 and 6640451605.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4078088 + ... + 4079715.

It is an arithmetic number, because the mean of its divisors is an integer number (697492242).

Almost surely, 2^6640451642 is an apocalyptic number.

6640451642 is a deficient number, since it is larger than the sum of its proper divisors (4519424230).

6640451642 is a wasteful number, since it uses less digits than its factorization.

6640451642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8157853.

The product of its (nonzero) digits is 138240, while the sum is 38.

The square root of 6640451642 is about 81488.9663819587. The cubic root of 6640451642 is about 1879.6018888794.

The spelling of 6640451642 in words is "six billion, six hundred forty million, four hundred fifty-one thousand, six hundred forty-two".