1664428500 has 576 divisors, whose sum is σ = 6614200320. Its totient is φ = 356918400.

The previous prime is 1664428421. The next prime is 1664428553. The reversal of 1664428500 is 58244661.

1664428500 is a `hidden beast` number, since 1 + 6 + 644 + 2 + 8 + 5 + 0 + 0 = 666.

It is a super-2 number, since 2×1664428500² = 5540644463224500000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 16159449 + ... + 16159551.

Almost surely, 2^1664428500 is an apocalyptic number.

1664428500 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 1664428500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3307100160).

1664428500 is an abundant number, since it is smaller than the sum of its proper divisors (4949771820).

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

1664428500 is a wasteful number, since it uses less digits than its factorization.

1664428500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 1664428500 is about 40797.4080059016. The cubic root of 1664428500 is about 1185.1001357457.

The spelling of 1664428500 in words is "one billion, six hundred sixty-four million, four hundred twenty-eight thousand, five hundred".