2687721497 has 4 divisors (see below), whose sum is σ = 2693929140. Its totient is φ = 2681513856.

The previous prime is 2687721473. The next prime is 2687721499. The reversal of 2687721497 is 7941277862.

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 600054016 + 2087667481 = 24496^2 + 45691^2 .

It is a cyclic number.

It is not a de Polignac number, because 2687721497 - 2⁸ = 2687721241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2687721499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3103172 + ... + 3104037.

It is an arithmetic number, because the mean of its divisors is an integer number (673482285).

Almost surely, 2^2687721497 is an apocalyptic number.

It is an amenable number.

2687721497 is a deficient number, since it is larger than the sum of its proper divisors (6207643).

2687721497 is an equidigital number, since it uses as much as digits as its factorization.

2687721497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6207642.

The product of its digits is 2370816, while the sum is 53.

The square root of 2687721497 is about 51843.2396460715. The cubic root of 2687721497 is about 1390.3626362639.

The spelling of 2687721497 in words is "two billion, six hundred eighty-seven million, seven hundred twenty-one thousand, four hundred ninety-seven".