646143820 has 48 divisors (see below), whose sum is σ = 1641971520. Its totient is φ = 208502784.

The previous prime is 646143793. The next prime is 646143859. The reversal of 646143820 is 28341646.

646143820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×646143820² = 835003672248384800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133365 + ... + 138124.

It is an arithmetic number, because the mean of its divisors is an integer number (34207740).

Almost surely, 2^646143820 is an apocalyptic number.

It is an amenable number.

646143820 is an abundant number, since it is smaller than the sum of its proper divisors (995827700).

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

646143820 is a wasteful number, since it uses less digits than its factorization.

646143820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271522 (or 271520 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 646143820 is about 25419.3591579332. The cubic root of 646143820 is about 864.5226943384.

The spelling of 646143820 in words is "six hundred forty-six million, one hundred forty-three thousand, eight hundred twenty".