1641064320 has 256 divisors, whose sum is σ = 6642892800. Its totient is φ = 375072768.

The previous prime is 1641064307. The next prime is 1641064331. The reversal of 1641064320 is 234601461.

1641064320 is a `hidden beast` number, since 1 + 6 + 4 + 10 + 643 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 114177 + ... + 127743.

It is an arithmetic number, because the mean of its divisors is an integer number (25948800).

Almost surely, 2^1641064320 is an apocalyptic number.

1641064320 is a gapful number since it is divisible by the number (10) 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 1641064320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3321446400).

1641064320 is an abundant number, since it is smaller than the sum of its proper divisors (5001828480).

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

1641064320 is a wasteful number, since it uses less digits than its factorization.

1641064320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13602 (or 13584 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 1641064320 is about 40510.0520858712. The cubic root of 1641064320 is about 1179.5287594525.

Adding to 1641064320 its reverse (234601461), we get a palindrome (1875665781).

The spelling of 1641064320 in words is "one billion, six hundred forty-one million, sixty-four thousand, three hundred twenty".