640949948 has 6 divisors (see below), whose sum is σ = 1121662416. Its totient is φ = 320474972.

The previous prime is 640949923. The next prime is 640949983. The reversal of 640949948 is 849949046.

It is a happy number.

640949948 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 640949948.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80118740 + ... + 80118747.

It is an arithmetic number, because the mean of its divisors is an integer number (186943736).

Almost surely, 2^640949948 is an apocalyptic number.

It is an amenable number.

640949948 is a deficient number, since it is larger than the sum of its proper divisors (480712468).

640949948 is a wasteful number, since it uses less digits than its factorization.

640949948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160237491 (or 160237489 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 53.

The square root of 640949948 is about 25316.9893154775. The cubic root of 640949948 is about 862.2000404239.

The spelling of 640949948 in words is "six hundred forty million, nine hundred forty-nine thousand, nine hundred forty-eight".