1165664640 has 256 divisors, whose sum is σ = 4347256320. Its totient is φ = 260112384.

The previous prime is 1165664629. The next prime is 1165664641. The reversal of 1165664640 is 464665611.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1165664641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 576912 + ... + 578928.

It is an arithmetic number, because the mean of its divisors is an integer number (16981470).

Almost surely, 2^1165664640 is an apocalyptic number.

1165664640 is a gapful number since it is divisible by the number (10) 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 1165664640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2173628160).

1165664640 is an abundant number, since it is smaller than the sum of its proper divisors (3181591680).

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

1165664640 is a wasteful number, since it uses less digits than its factorization.

1165664640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2089 (or 2077 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 1165664640 is about 34141.8312338398. The cubic root of 1165664640 is about 1052.4251246754.

The spelling of 1165664640 in words is "one billion, one hundred sixty-five million, six hundred sixty-four thousand, six hundred forty".