1664163840 has 224 divisors, whose sum is σ = 5520415680. Its totient is φ = 427556864.

The previous prime is 1664163829. The next prime is 1664163841. The reversal of 1664163840 is 483614661.

It is a super-3 number, since 3×1664163840³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1664163841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3563287 + ... + 3563753.

Almost surely, 2^1664163840 is an apocalyptic number.

1664163840 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 1664163840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2760207840).

1664163840 is an abundant number, since it is smaller than the sum of its proper divisors (3856251840).

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

1664163840 is an equidigital number, since it uses as much as digits as its factorization.

1664163840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530 (or 506 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 1664163840 is about 40794.1642885352. The cubic root of 1664163840 is about 1185.0373183426.

The spelling of 1664163840 in words is "one billion, six hundred sixty-four million, one hundred sixty-three thousand, eight hundred forty".