2665720538 has 8 divisors (see below), whose sum is σ = 4306163988. Its totient is φ = 1230332544.

The previous prime is 2665720531. The next prime is 2665720559. The reversal of 2665720538 is 8350275662.

It can be written as a sum of positive squares in 2 ways, for example, as 2460457609 + 205262929 = 49603^2 + 14327^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (2665720531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51263831 + ... + 51263882.

Almost surely, 2^2665720538 is an apocalyptic number.

2665720538 is a deficient number, since it is larger than the sum of its proper divisors (1640443450).

2665720538 is a wasteful number, since it uses less digits than its factorization.

2665720538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102527728.

The product of its (nonzero) digits is 604800, while the sum is 44.

The square root of 2665720538 is about 51630.6162853011. The cubic root of 2665720538 is about 1386.5585270570.

The spelling of 2665720538 in words is "two billion, six hundred sixty-five million, seven hundred twenty thousand, five hundred thirty-eight".