640299234969 has 27 divisors (see below), whose sum is σ = 947038310517. Its totient is φ = 416871821016.

The previous prime is 640299234947. The next prime is 640299235021. The reversal of 640299234969 is 969432992046.

The square root of 640299234969 is 800187.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 640299234969 - 2¹⁷ = 640299103897 is a prime.

It is a super-2 number, since 2×640299234969² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (640299234929) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 103221022 + ... + 103227224.

Almost surely, 2^640299234969 is an apocalyptic number.

640299234969 is the 800187-th square number.

640299234969 is the 400094-th centered octagonal number.

It is an amenable number.

640299234969 is a deficient number, since it is larger than the sum of its proper divisors (306739075548).

640299234969 is an frugal number, since it uses more digits than its factorization.

640299234969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12498 (or 6249 counting only the distinct ones).

The product of its (nonzero) digits is 45349632, while the sum is 63.

The spelling of 640299234969 in words is "six hundred forty billion, two hundred ninety-nine million, two hundred thirty-four thousand, nine hundred sixty-nine".