1640272128 has 216 divisors, whose sum is σ = 5056447200. Its totient is φ = 470384640.

The previous prime is 1640272121. The next prime is 1640272133. The reversal of 1640272128 is 8212720461.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (1640272121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1765168 + ... + 1766096.

Almost surely, 2^1640272128 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 1640272128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2528223600).

1640272128 is an abundant number, since it is smaller than the sum of its proper divisors (3416175072).

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

1640272128 is a wasteful number, since it uses less digits than its factorization.

1640272128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989 (or 964 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 1640272128 is about 40500.2731842638. The cubic root of 1640272128 is about 1179.3389306866.

Adding to 1640272128 its reverse (8212720461), we get a palindrome (9852992589).

The spelling of 1640272128 in words is "one billion, six hundred forty million, two hundred seventy-two thousand, one hundred twenty-eight".