1665333261 has 12 divisors (see below), whose sum is σ = 2532085920. Its totient is φ = 1051789320.

The previous prime is 1665333251. The next prime is 1665333287. The reversal of 1665333261 is 1623335661.

1665333261 is a `hidden beast` number, since 1 + 6 + 65 + 333 + 261 = 666.

It is not a de Polignac number, because 1665333261 - 2⁷ = 1665333133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665333251) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4869225 + ... + 4869566.

It is an arithmetic number, because the mean of its divisors is an integer number (211007160).

Almost surely, 2^1665333261 is an apocalyptic number.

It is an amenable number.

1665333261 is a deficient number, since it is larger than the sum of its proper divisors (866752659).

1665333261 is a wasteful number, since it uses less digits than its factorization.

1665333261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9738816 (or 9738813 counting only the distinct ones).

The product of its digits is 58320, while the sum is 36.

The square root of 1665333261 is about 40808.4949612210. The cubic root of 1665333261 is about 1185.3148316926.

The spelling of 1665333261 in words is "one billion, six hundred sixty-five million, three hundred thirty-three thousand, two hundred sixty-one".