1165661500 has 24 divisors (see below), whose sum is σ = 2545805808. Its totient is φ = 466264400.

The previous prime is 1165661477. The next prime is 1165661507. The reversal of 1165661500 is 51665611.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1165661507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1165162 + ... + 1166161.

It is an arithmetic number, because the mean of its divisors is an integer number (106075242).

Almost surely, 2^1165661500 is an apocalyptic number.

1165661500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1165661500 is an abundant number, since it is smaller than the sum of its proper divisors (1380144308).

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

1165661500 is a wasteful number, since it uses less digits than its factorization.

1165661500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2331342 (or 2331330 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 1165661500 is about 34141.7852491635. The cubic root of 1165661500 is about 1052.4241796872.

The spelling of 1165661500 in words is "one billion, one hundred sixty-five million, six hundred sixty-one thousand, five hundred".