2665642500 has 480 divisors, whose sum is σ = 9635915520. Its totient is φ = 633600000.

The previous prime is 2665642489. The next prime is 2665642501. The reversal of 2665642500 is 52465662.

2665642500 is a `hidden beast` number, since 2 + 6 + 6 + 5 + 642 + 5 + 0 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2665642501) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 26392450 + ... + 26392550.

It is an arithmetic number, because the mean of its divisors is an integer number (20074824).

Almost surely, 2^2665642500 is an apocalyptic number.

2665642500 is a gapful number since it is divisible by the number (20) 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 2665642500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4817957760).

2665642500 is an abundant number, since it is smaller than the sum of its proper divisors (6970273020).

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

2665642500 is a wasteful number, since it uses less digits than its factorization.

2665642500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 2665642500 is about 51629.8605460057. The cubic root of 2665642500 is about 1386.5449965927.

The spelling of 2665642500 in words is "two billion, six hundred sixty-five million, six hundred forty-two thousand, five hundred".