646219056 has 120 divisors (see below), whose sum is σ = 2004824064. Its totient is φ = 178657920.

The previous prime is 646219039. The next prime is 646219061. The reversal of 646219056 is 650912646.

It is a super-2 number, since 2×646219056² = 835198136675062272, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68481 + ... + 77343.

Almost surely, 2^646219056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646219056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1002412032).

646219056 is an abundant number, since it is smaller than the sum of its proper divisors (1358605008).

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

646219056 is a wasteful number, since it uses less digits than its factorization.

646219056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8919 (or 8906 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 646219056 is about 25420.8390105441. The cubic root of 646219056 is about 864.5562476037.

The spelling of 646219056 in words is "six hundred forty-six million, two hundred nineteen thousand, fifty-six".