640246642 has 24 divisors (see below), whose sum is σ = 1136110320. Its totient is φ = 269738280.

The previous prime is 640246637. The next prime is 640246669. The reversal of 640246642 is 246642046.

It is a junction number, because it is equal to n+sod(n) for n = 640246598 and 640246607.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49584 + ... + 61147.

It is an arithmetic number, because the mean of its divisors is an integer number (47337930).

Almost surely, 2^640246642 is an apocalyptic number.

640246642 is a deficient number, since it is larger than the sum of its proper divisors (495863678).

640246642 is a wasteful number, since it uses less digits than its factorization.

640246642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110806 (or 110799 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 34.

The square root of 640246642 is about 25303.0955023294. The cubic root of 640246642 is about 861.8845647285.

Adding to 640246642 its reverse (246642046), we get a palindrome (886888688).

The spelling of 640246642 in words is "six hundred forty million, two hundred forty-six thousand, six hundred forty-two".