501688890 has 60 divisors (see below), whose sum is σ = 1350701946. Its totient is φ = 133613712.

The previous prime is 501688879. The next prime is 501688909. The reversal of 501688890 is 98886105.

501688890 is a `hidden beast` number, since 501 + 68 + 8 + 89 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 451520001 + 50168889 = 21249^2 + 7083^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 637077 + ... + 637863.

Almost surely, 2^501688890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 501688890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (675350973).

501688890 is an abundant number, since it is smaller than the sum of its proper divisors (849013056).

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

501688890 is an frugal number, since it uses more digits than its factorization.

501688890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1593 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 501688890 is about 22398.4126669726. The cubic root of 501688890 is about 794.5931702728.

The spelling of 501688890 in words is "five hundred one million, six hundred eighty-eight thousand, eight hundred ninety".