1640738736 has 360 divisors, whose sum is σ = 5948202624. Its totient is φ = 418037760.

The previous prime is 1640738719. The next prime is 1640738773. The reversal of 1640738736 is 6378370461.

It is a junction number, because it is equal to n+sod(n) for n = 1640738691 and 1640738700.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 2843280 + ... + 2843856.

Almost surely, 2^1640738736 is an apocalyptic number.

1640738736 is a gapful number since it is divisible by the number (16) 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 1640738736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2974101312).

1640738736 is an abundant number, since it is smaller than the sum of its proper divisors (4307463888).

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

1640738736 is a wasteful number, since it uses less digits than its factorization.

1640738736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649 (or 633 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The square root of 1640738736 is about 40506.0333283821. The cubic root of 1640738736 is about 1179.4507488820.

The spelling of 1640738736 in words is "one billion, six hundred forty million, seven hundred thirty-eight thousand, seven hundred thirty-six".