640621623323 has 16 divisors (see below), whose sum is σ = 704065850880. Its totient is φ = 578047168800.

The previous prime is 640621623319. The next prime is 640621623329. The reversal of 640621623323 is 323326126046.

It is a cyclic number.

It is not a de Polignac number, because 640621623323 - 2² = 640621623319 is a prime.

It is a super-3 number, since 3×640621623323³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640621623329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6234761 + ... + 6336677.

It is an arithmetic number, because the mean of its divisors is an integer number (44004115680).

Almost surely, 2^640621623323 is an apocalyptic number.

640621623323 is a deficient number, since it is larger than the sum of its proper divisors (63444227557).

640621623323 is a wasteful number, since it uses less digits than its factorization.

640621623323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106178.

The product of its (nonzero) digits is 186624, while the sum is 38.

Adding to 640621623323 its reverse (323326126046), we get a palindrome (963947749369).

The spelling of 640621623323 in words is "six hundred forty billion, six hundred twenty-one million, six hundred twenty-three thousand, three hundred twenty-three".