1640448640 has 48 divisors (see below), whose sum is σ = 3924148590. Its totient is φ = 655769600.

The previous prime is 1640448637. The next prime is 1640448659. The reversal of 1640448640 is 468440461.

It can be written as a sum of positive squares in 3 ways, for example, as 1522248256 + 118200384 = 39016^2 + 10872^2 .

It is a super-3 number, since 3×1640448640³ (a number of 29 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1640448640.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 1023840 + ... + 1025440.

Almost surely, 2^1640448640 is an apocalyptic number.

1640448640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1640448640 is an abundant number, since it is smaller than the sum of its proper divisors (2283699950).

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

1640448640 is an frugal number, since it uses more digits than its factorization.

1640448640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3221 (or 1608 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 37.

The square root of 1640448640 is about 40502.4522714366. The cubic root of 1640448640 is about 1179.3812326118.

The spelling of 1640448640 in words is "one billion, six hundred forty million, four hundred forty-eight thousand, six hundred forty".