1640216256 has 112 divisors (see below), whose sum is σ = 4975408896. Its totient is φ = 467149824.

The previous prime is 1640216189. The next prime is 1640216257. The reversal of 1640216256 is 6526120461.

It is a tau number, because it is divible by the number of its divisors (112).

It is not an unprimeable number, because it can be changed into a prime (1640216257) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 464610 + ... + 468126.

Almost surely, 2^1640216256 is an apocalyptic number.

1640216256 is a gapful number since it is divisible by the number (16) 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 1640216256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2487704448).

1640216256 is an abundant number, since it is smaller than the sum of its proper divisors (3335192640).

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

1640216256 is a wasteful number, since it uses less digits than its factorization.

1640216256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886 (or 3876 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 1640216256 is about 40499.5834052648. The cubic root of 1640216256 is about 1179.3255400685.

The spelling of 1640216256 in words is "one billion, six hundred forty million, two hundred sixteen thousand, two hundred fifty-six".