7642081561 has 27 divisors (see below), whose sum is σ = 8335289781. Its totient is φ = 7005408984.

The previous prime is 7642081549. The next prime is 7642081597. The reversal of 7642081561 is 1651802467.

The square root of 7642081561 is 87419.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 7642081561 - 2⁹ = 7642081049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7642081541) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 71421270 + ... + 71421376.

Almost surely, 2^7642081561 is an apocalyptic number.

7642081561 is the 87419-th square number.

7642081561 is the 43710-th centered octagonal number.

It is an amenable number.

7642081561 is a deficient number, since it is larger than the sum of its proper divisors (693208220).

7642081561 is an equidigital number, since it uses as much as digits as its factorization.

7642081561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The cubic root of 7642081561 is about 1969.7172553231.

The spelling of 7642081561 in words is "seven billion, six hundred forty-two million, eighty-one thousand, five hundred sixty-one".