7217652991761 has 27 divisors (see below), whose sum is σ = 10575243357627. Its totient is φ = 4743621151920.

The previous prime is 7217652991741. The next prime is 7217652991777. The reversal of 7217652991761 is 1671992567127.

The square root of 7217652991761 is 2686569.

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

7217652991761 is a `hidden beast` number, since 7 + 2 + 17 + 6 + 529 + 91 + 7 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3046892436225 + 4170760555536 = 1745535^2 + 2042244^2 .

It is not a de Polignac number, because 7217652991761 - 2⁹ = 7217652991249 is a prime.

It is a super-2 number, since 2×7217652991761² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7217652991741) 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 26 ways as a sum of consecutive naturals, for example, 572232891 + ... + 572245503.

Almost surely, 2^{7217652991761} is an apocalyptic number.

7217652991761 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

7217652991761 is the 2686569-th square number.

7217652991761 is the 1343285-th centered octagonal number.

It is an amenable number.

7217652991761 is a deficient number, since it is larger than the sum of its proper divisors (3357590365866).

7217652991761 is an frugal number, since it uses more digits than its factorization.

7217652991761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25374 (or 12687 counting only the distinct ones).

The product of its digits is 20003760, while the sum is 63.

The spelling of 7217652991761 in words is "seven trillion, two hundred seventeen billion, six hundred fifty-two million, nine hundred ninety-one thousand, seven hundred sixty-one".