1643966464 has 78 divisors (see below), whose sum is σ = 3824738304. Its totient is φ = 704471040.

The previous prime is 1643966353. The next prime is 1643966477. The reversal of 1643966464 is 4646693461.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 196609 + ... + 204799.

Almost surely, 2^1643966464 is an apocalyptic number.

1643966464 is a gapful number since it is divisible by the number (14) 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 1643966464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1912369152).

1643966464 is an abundant number, since it is smaller than the sum of its proper divisors (2180771840).

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

1643966464 is an frugal number, since it uses more digits than its factorization.

1643966464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8229 (or 8200 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 49.

The square root of 1643966464 is about 40545.8563110955. The cubic root of 1643966464 is about 1180.2236634346.

1643966464 divided by its sum of digits (49) gives a triangular number (33550336 = T₈₁₉₁).

The spelling of 1643966464 in words is "one billion, six hundred forty-three million, nine hundred sixty-six thousand, four hundred sixty-four".