646589628 has 120 divisors (see below), whose sum is σ = 1811224800. Its totient is φ = 200420352.

The previous prime is 646589609. The next prime is 646589663. The reversal of 646589628 is 826985646.

It is a happy number.

646589628 is a `hidden beast` number, since 6 + 4 + 6 + 5 + 8 + 9 + 628 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 489553 + ... + 490871.

It is an arithmetic number, because the mean of its divisors is an integer number (15093540).

Almost surely, 2^646589628 is an apocalyptic number.

646589628 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646589628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (905612400).

646589628 is an abundant number, since it is smaller than the sum of its proper divisors (1164635172).

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

646589628 is a wasteful number, since it uses less digits than its factorization.

646589628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1441 (or 1430 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 54.

The square root of 646589628 is about 25428.1267103969. The cubic root of 646589628 is about 864.7214749179.

The spelling of 646589628 in words is "six hundred forty-six million, five hundred eighty-nine thousand, six hundred twenty-eight".