2506543665 has 16 divisors (see below), whose sum is σ = 4246380288. Its totient is φ = 1258186496.

The previous prime is 2506543639. The next prime is 2506543667. The reversal of 2506543665 is 5663456052.

It is a cyclic number.

It is not a de Polignac number, because 2506543665 - 2⁷ = 2506543537 is a prime.

It is a super-2 number, since 2×2506543665² = 12565522289103264450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2506543667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4914537 + ... + 4915046.

It is an arithmetic number, because the mean of its divisors is an integer number (265398768).

Almost surely, 2^2506543665 is an apocalyptic number.

It is an amenable number.

2506543665 is a deficient number, since it is larger than the sum of its proper divisors (1739836623).

2506543665 is a wasteful number, since it uses less digits than its factorization.

2506543665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9829608.

The product of its (nonzero) digits is 648000, while the sum is 42.

The square root of 2506543665 is about 50065.3938863962. The cubic root of 2506543665 is about 1358.3919259439.

The spelling of 2506543665 in words is "two billion, five hundred six million, five hundred forty-three thousand, six hundred sixty-five".