7191221761 has 4 divisors (see below), whose sum is σ = 7261039552. Its totient is φ = 7121403972.

The previous prime is 7191221743. The next prime is 7191221777. The reversal of 7191221761 is 1671221917.

7191221761 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1671221917 = 53 ⋅31532489.

It is a cyclic number.

It is not a de Polignac number, because 7191221761 - 2²⁵ = 7157667329 is a prime.

It is a super-2 number, since 2×7191221761² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7191221761.

It is not an unprimeable number, because it can be changed into a prime (7191221861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34908741 + ... + 34908946.

It is an arithmetic number, because the mean of its divisors is an integer number (1815259888).

Almost surely, 2^7191221761 is an apocalyptic number.

It is an amenable number.

7191221761 is a deficient number, since it is larger than the sum of its proper divisors (69817791).

7191221761 is a wasteful number, since it uses less digits than its factorization.

7191221761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69817790.

The product of its digits is 10584, while the sum is 37.

The square root of 7191221761 is about 84801.0716972374. The cubic root of 7191221761 is about 1930.1937003904.

The spelling of 7191221761 in words is "seven billion, one hundred ninety-one million, two hundred twenty-one thousand, seven hundred sixty-one".