438658317990 has 160 divisors (see below), whose sum is σ = 1252196146080. Its totient is φ = 109802843136.

The previous prime is 438658317983. The next prime is 438658317991. The reversal of 438658317990 is 99713856834.

438658317990 is a `hidden beast` number, since 4 + 38 + 6 + 583 + 17 + 9 + 9 + 0 = 666.

It is a super-2 number, since 2×438658317990² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (438658317991) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 5176804 + ... + 5260856.

It is an arithmetic number, because the mean of its divisors is an integer number (7826225913).

Almost surely, 2^438658317990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 438658317990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (626098073040).

438658317990 is an abundant number, since it is smaller than the sum of its proper divisors (813537828090).

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

438658317990 is a wasteful number, since it uses less digits than its factorization.

438658317990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84468 (or 84459 counting only the distinct ones).

The product of its (nonzero) digits is 39191040, while the sum is 63.

The spelling of 438658317990 in words is "four hundred thirty-eight billion, six hundred fifty-eight million, three hundred seventeen thousand, nine hundred ninety".