664558237890 has 320 divisors, whose sum is σ = 1897759632384. Its totient is φ = 166512246912.

The previous prime is 664558237853. The next prime is 664558237891. The reversal of 664558237890 is 98732855466.

It is a happy number.

664558237890 is a `hidden beast` number, since 6 + 6 + 4 + 558 + 2 + 3 + 78 + 9 + 0 = 666.

664558237890 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (664558237891) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 732698817 + ... + 732699723.

Almost surely, 2^664558237890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664558237890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (948879816192).

664558237890 is an abundant number, since it is smaller than the sum of its proper divisors (1233201394494).

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

664558237890 is a wasteful number, since it uses less digits than its factorization.

664558237890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1603 (or 1594 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 63.

The spelling of 664558237890 in words is "six hundred sixty-four billion, five hundred fifty-eight million, two hundred thirty-seven thousand, eight hundred ninety".