640104023666 has 16 divisors (see below), whose sum is σ = 979383681600. Its totient is φ = 313690806000.

The previous prime is 640104023653. The next prime is 640104023707. The reversal of 640104023666 is 666320401046.

It is a happy number.

It is a super-2 number, since 2×640104023666² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

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, 11975585 + ... + 12028916.

It is an arithmetic number, because the mean of its divisors is an integer number (61211480100).

Almost surely, 2^640104023666 is an apocalyptic number.

640104023666 is a deficient number, since it is larger than the sum of its proper divisors (339279657934).

640104023666 is a wasteful number, since it uses less digits than its factorization.

640104023666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24004769.

The product of its (nonzero) digits is 124416, while the sum is 38.

The spelling of 640104023666 in words is "six hundred forty billion, one hundred four million, twenty-three thousand, six hundred sixty-six".