7727640649 has 9 divisors (see below), whose sum is σ = 8210534791. Its totient is φ = 7271667040.

The previous prime is 7727640619. The next prime is 7727640719. The reversal of 7727640649 is 9460467277.

The square root of 7727640649 is 87907.

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

It can be written as a sum of positive squares in only one way, i.e., 6016329225 + 1711311424 = 77565^2 + 41368^2 .

It is not a de Polignac number, because 7727640649 - 2⁷ = 7727640521 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7727640596 and 7727640605.

It is not an unprimeable number, because it can be changed into a prime (7727640619) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1491834 + ... + 1497004.

Almost surely, 2^7727640649 is an apocalyptic number.

7727640649 is the 87907-th square number.

7727640649 is the 43954-th centered octagonal number.

It is an amenable number.

7727640649 is a deficient number, since it is larger than the sum of its proper divisors (482894142).

7727640649 is an frugal number, since it uses more digits than its factorization.

7727640649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10376 (or 5188 counting only the distinct ones).

The product of its (nonzero) digits is 3556224, while the sum is 52.

The cubic root of 7727640649 is about 1977.0408342977.

The spelling of 7727640649 in words is "seven billion, seven hundred twenty-seven million, six hundred forty thousand, six hundred forty-nine".