1640439380 has 24 divisors (see below), whose sum is σ = 3493445760. Its totient is φ = 646933280.

The previous prime is 1640439331. The next prime is 1640439391. The reversal of 1640439380 is 839340461.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 576200 + ... + 579039.

It is an arithmetic number, because the mean of its divisors is an integer number (145560240).

Almost surely, 2^1640439380 is an apocalyptic number.

1640439380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1640439380 is an abundant number, since it is smaller than the sum of its proper divisors (1853006380).

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

1640439380 is a wasteful number, since it uses less digits than its factorization.

1640439380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1155319 (or 1155317 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 1640439380 is about 40502.3379572093. The cubic root of 1640439380 is about 1179.3790134850.

The spelling of 1640439380 in words is "one billion, six hundred forty million, four hundred thirty-nine thousand, three hundred eighty".