1165601511 has 6 divisors (see below), whose sum is σ = 1683646640. Its totient is φ = 777067668.

The previous prime is 1165601497. The next prime is 1165601539. The reversal of 1165601511 is 1151065611.

1165601511 is a `hidden beast` number, since 1 + 1 + 6 + 5 + 601 + 51 + 1 = 666.

It is not a de Polignac number, because 1165601511 - 2¹⁰ = 1165600487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1165601011) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 64755631 + ... + 64755648.

Almost surely, 2^1165601511 is an apocalyptic number.

1165601511 is a deficient number, since it is larger than the sum of its proper divisors (518045129).

1165601511 is a wasteful number, since it uses less digits than its factorization.

1165601511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129511285 (or 129511282 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 27.

The square root of 1165601511 is about 34140.9067102794. The cubic root of 1165601511 is about 1052.4061255731.

The spelling of 1165601511 in words is "one billion, one hundred sixty-five million, six hundred one thousand, five hundred eleven".