1640120340 has 96 divisors (see below), whose sum is σ = 4802789376. Its totient is φ = 417408640.

The previous prime is 1640120333. The next prime is 1640120371. The reversal of 1640120340 is 430210461.

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, 775885 + ... + 777995.

It is an arithmetic number, because the mean of its divisors is an integer number (50029056).

Almost surely, 2^1640120340 is an apocalyptic number.

1640120340 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 1640120340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2401394688).

1640120340 is an abundant number, since it is smaller than the sum of its proper divisors (3162669036).

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

1640120340 is a wasteful number, since it uses less digits than its factorization.

1640120340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709 (or 2707 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 1640120340 is about 40498.3992276238. The cubic root of 1640120340 is about 1179.3025515565.

The spelling of 1640120340 in words is "one billion, six hundred forty million, one hundred twenty thousand, three hundred forty".