2009257640 has 128 divisors (see below), whose sum is σ = 4998913920. Its totient is φ = 722304000.

The previous prime is 2009257631. The next prime is 2009257643. The reversal of 2009257640 is 467529002.

It is a self number, because there is not a number n which added to its sum of digits gives 2009257640.

It is not an unprimeable number, because it can be changed into a prime (2009257643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3518555 + ... + 3519125.

It is an arithmetic number, because the mean of its divisors is an integer number (39054015).

Almost surely, 2^2009257640 is an apocalyptic number.

2009257640 is a gapful number since it is divisible by the number (20) 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 2009257640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2499456960).

2009257640 is an abundant number, since it is smaller than the sum of its proper divisors (2989656280).

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

2009257640 is a wasteful number, since it uses less digits than its factorization.

2009257640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 763 (or 759 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 2009257640 is about 44824.7436133214. The cubic root of 2009257640 is about 1261.8620407207.

The spelling of 2009257640 in words is "two billion, nine million, two hundred fifty-seven thousand, six hundred forty".