2539709665 has 4 divisors (see below), whose sum is σ = 3047651604. Its totient is φ = 2031767728.

The previous prime is 2539709621. The next prime is 2539709671. The reversal of 2539709665 is 5669079352.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 515789521 + 2023920144 = 22711^2 + 44988^2 .

It is a cyclic number.

It is not a de Polignac number, because 2539709665 - 2¹³ = 2539701473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 253970962 + ... + 253970971.

It is an arithmetic number, because the mean of its divisors is an integer number (761912901).

Almost surely, 2^2539709665 is an apocalyptic number.

It is an amenable number.

2539709665 is a deficient number, since it is larger than the sum of its proper divisors (507941939).

2539709665 is an equidigital number, since it uses as much as digits as its factorization.

2539709665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507941938.

The product of its (nonzero) digits is 3061800, while the sum is 52.

The square root of 2539709665 is about 50395.5321928442. The cubic root of 2539709665 is about 1364.3570014715.

The spelling of 2539709665 in words is "two billion, five hundred thirty-nine million, seven hundred nine thousand, six hundred sixty-five".