117651651721 has 4 divisors (see below), whose sum is σ = 120521204244. Its totient is φ = 114782099200.

The previous prime is 117651651709. The next prime is 117651651731. The reversal of 117651651721 is 127156156711.

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 54833247225 + 62818404496 = 234165^2 + 250636^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-117651651721 is a prime.

It is a super-2 number, since 2×117651651721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (117651651731) 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, 1434776200 + ... + 1434776281.

It is an arithmetic number, because the mean of its divisors is an integer number (30130301061).

Almost surely, 2^117651651721 is an apocalyptic number.

It is an amenable number.

117651651721 is a deficient number, since it is larger than the sum of its proper divisors (2869552523).

117651651721 is an equidigital number, since it uses as much as digits as its factorization.

117651651721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2869552522.

The product of its digits is 88200, while the sum is 43.

The spelling of 117651651721 in words is "one hundred seventeen billion, six hundred fifty-one million, six hundred fifty-one thousand, seven hundred twenty-one".