1645769664 has 840 divisors, whose sum is σ = 6727057920. Its totient is φ = 391910400.

The previous prime is 1645769663. The next prime is 1645769681. The reversal of 1645769664 is 4669675461.

1645769664 is a `hidden beast` number, since 1 + 6 + 4 + 576 + 9 + 6 + 64 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 1645769664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645769663) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 53089329 + ... + 53089359.

Almost surely, 2^1645769664 is an apocalyptic number.

1645769664 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 1645769664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3363528960).

1645769664 is an abundant number, since it is smaller than the sum of its proper divisors (5081288256).

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

1645769664 is a wasteful number, since it uses less digits than its factorization.

1645769664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 73 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 54.

The square root of 1645769664 is about 40568.0867678031. The cubic root of 1645769664 is about 1180.6550188842.

The spelling of 1645769664 in words is "one billion, six hundred forty-five million, seven hundred sixty-nine thousand, six hundred sixty-four".