638453420368 has 40 divisors (see below), whose sum is σ = 1241344555560. Its totient is φ = 318108057600.

The previous prime is 638453420351. The next prime is 638453420377. The reversal of 638453420368 is 863024354836.

It can be written as a sum of positive squares in 4 ways, for example, as 299156490304 + 339296930064 = 546952^2 + 582492^2 .

It is a congruent 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, 6346848 + ... + 6446656.

It is an arithmetic number, because the mean of its divisors is an integer number (31033613889).

Almost surely, 2^638453420368 is an apocalyptic number.

It is an amenable number.

638453420368 is a deficient number, since it is larger than the sum of its proper divisors (602891135192).

638453420368 is a wasteful number, since it uses less digits than its factorization.

638453420368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101215 (or 101209 counting only the distinct ones).

The product of its (nonzero) digits is 9953280, while the sum is 52.

The spelling of 638453420368 in words is "six hundred thirty-eight billion, four hundred fifty-three million, four hundred twenty thousand, three hundred sixty-eight".