640250766 has 24 divisors (see below), whose sum is σ = 1387890504. Its totient is φ = 213312240.

The previous prime is 640250761. The next prime is 640250783. The reversal of 640250766 is 667052046.

640250766 is a `hidden beast` number, since 640 + 2 + 5 + 0 + 7 + 6 + 6 = 666.

640250766 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 640250766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640250761) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34881 + ... + 49971.

It is an arithmetic number, because the mean of its divisors is an integer number (57828771).

Almost surely, 2^640250766 is an apocalyptic number.

640250766 is an abundant number, since it is smaller than the sum of its proper divisors (747639738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640250766 is a wasteful number, since it uses less digits than its factorization.

640250766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17456 (or 17453 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 640250766 is about 25303.1769942037. The cubic root of 640250766 is about 861.8864152676.

The spelling of 640250766 in words is "six hundred forty million, two hundred fifty thousand, seven hundred sixty-six".