640008248 has 32 divisors (see below), whose sum is σ = 1386117360. Its totient is φ = 273799680.

The previous prime is 640008247. The next prime is 640008251. The reversal of 640008248 is 842800046.

It is a super-2 number, since 2×640008248² = 819221115016059008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640008247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212411 + ... + 215402.

Almost surely, 2^640008248 is an apocalyptic number.

640008248 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

640008248 is an abundant number, since it is smaller than the sum of its proper divisors (746109112).

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

640008248 is a wasteful number, since it uses less digits than its factorization.

640008248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427847 (or 427843 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 32.

The square root of 640008248 is about 25298.3842962352. The cubic root of 640008248 is about 861.7775780338. Note that the first 3 decimals are identical.

The spelling of 640008248 in words is "six hundred forty million, eight thousand, two hundred forty-eight".