2645664 has 96 divisors (see below), whose sum is σ = 8257536. Its totient is φ = 725760.

The previous prime is 2645663. The next prime is 2645681. The reversal of 2645664 is 4665462.

2645664 = 277² + 278² + ... + 307².

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (2645663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20769 + ... + 20895.

It is an arithmetic number, because the mean of its divisors is an integer number (86016).

2^2645664 is an apocalyptic number.

2645664 is a gapful number since it is divisible by the number (24) 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 2645664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4128768).

2645664 is an abundant number, since it is smaller than the sum of its proper divisors (5611872).

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

2645664 is a wasteful number, since it uses less digits than its factorization.

2645664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178 (or 170 counting only the distinct ones).

The product of its digits is 34560, while the sum is 33.

The square root of 2645664 is about 1626.5497225723. The cubic root of 2645664 is about 138.3072339916.

The spelling of 2645664 in words is "two million, six hundred forty-five thousand, six hundred sixty-four".