2665406640 has 160 divisors (see below), whose sum is σ = 9366900480. Its totient is φ = 621554688.

The previous prime is 2665406633. The next prime is 2665406647. The reversal of 2665406640 is 466045662.

It is an interprime number because it is at equal distance from previous prime (2665406633) and next prime (2665406647).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (2665406647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36799 + ... + 81761.

It is an arithmetic number, because the mean of its divisors is an integer number (58543128).

Almost surely, 2^2665406640 is an apocalyptic number.

2665406640 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 2665406640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4683450240).

2665406640 is an abundant number, since it is smaller than the sum of its proper divisors (6701493840).

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

2665406640 is a wasteful number, since it uses less digits than its factorization.

2665406640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45011 (or 45005 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 39.

The square root of 2665406640 is about 51627.5763521783. The cubic root of 2665406640 is about 1386.5041008676.

The spelling of 2665406640 in words is "two billion, six hundred sixty-five million, four hundred six thousand, six hundred forty".