664070400 has 648 divisors, whose sum is σ = 2859997504. Its totient is φ = 149299200.

The previous prime is 664070389. The next prime is 664070411. The reversal of 664070400 is 4070466.

It is an interprime number because it is at equal distance from previous prime (664070389) and next prime (664070411).

It is a tau number, because it is divible by the number of its divisors (648).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 10886370 + ... + 10886430.

Almost surely, 2^664070400 is an apocalyptic number.

664070400 is a gapful number since it is divisible by the number (60) 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 664070400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1429998752).

664070400 is an abundant number, since it is smaller than the sum of its proper divisors (2195927104).

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

664070400 is an equidigital number, since it uses as much as digits as its factorization.

664070400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 664070400 is about 25769.5634421695. The cubic root of 664070400 is about 872.4449655081. Note that the first 3 decimals are identical.

The spelling of 664070400 in words is "six hundred sixty-four million, seventy thousand, four hundred".