1640826240 has 128 divisors (see below), whose sum is σ = 5243616000. Its totient is φ = 436426752.

The previous prime is 1640826227. The next prime is 1640826241. The reversal of 1640826240 is 426280461.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640826241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 964911 + ... + 966609.

It is an arithmetic number, because the mean of its divisors is an integer number (40965750).

Almost surely, 2^1640826240 is an apocalyptic number.

1640826240 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 1640826240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2621808000).

1640826240 is an abundant number, since it is smaller than the sum of its proper divisors (3602789760).

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

1640826240 is a wasteful number, since it uses less digits than its factorization.

1640826240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2224 (or 2212 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 33.

The square root of 1640826240 is about 40507.1134493684. The cubic root of 1640826240 is about 1179.4717160275.

The spelling of 1640826240 in words is "one billion, six hundred forty million, eight hundred twenty-six thousand, two hundred forty".