1664040000 has 420 divisors, whose sum is σ = 6422556624. Its totient is φ = 379008000.

The previous prime is 1664039989. The next prime is 1664040011. The reversal of 1664040000 is 404661.

It is an interprime number because it is at equal distance from previous prime (1664039989) and next prime (1664040011).

It is a tau number, because it is divible by the number of its divisors (420).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 5879859 + ... + 5880141.

Almost surely, 2^1664040000 is an apocalyptic number.

1664040000 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 1664040000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3211278312).

1664040000 is an abundant number, since it is smaller than the sum of its proper divisors (4758516624).

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

1664040000 is an equidigital number, since it uses as much as digits as its factorization.

1664040000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332 (or 300 counting only the distinct ones).

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

The square root of 1664040000 is about 40792.6463961337. The cubic root of 1664040000 is about 1185.0079224666.

Adding to 1664040000 its reverse (404661), we get a palindrome (1664444661).

The spelling of 1664040000 in words is "one billion, six hundred sixty-four million, forty thousand".