640023066 has 16 divisors (see below), whose sum is σ = 1422273600. Its totient is φ = 213341004.

The previous prime is 640023053. The next prime is 640023067. The reversal of 640023066 is 660320046.

640023066 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (640023067) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5926086 + ... + 5926193.

It is an arithmetic number, because the mean of its divisors is an integer number (88892100).

Almost surely, 2^640023066 is an apocalyptic number.

640023066 is an abundant number, since it is smaller than the sum of its proper divisors (782250534).

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

640023066 is a wasteful number, since it uses less digits than its factorization.

640023066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11852290 (or 11852284 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 640023066 is about 25298.6771590927. The cubic root of 640023066 is about 861.7842288447.

The spelling of 640023066 in words is "six hundred forty million, twenty-three thousand, sixty-six".