7751380221661 has 4 divisors (see below), whose sum is σ = 7752287567232. Its totient is φ = 7750472876092.

The previous prime is 7751380221647. The next prime is 7751380221751. The reversal of 7751380221661 is 1661220831577.

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.

It is a cyclic number.

It is not a de Polignac number, because 7751380221661 - 2³³ = 7742790287069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7751380221061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 453659971 + ... + 453677056.

It is an arithmetic number, because the mean of its divisors is an integer number (1938071891808).

Almost surely, 2^{7751380221661} is an apocalyptic number.

It is an amenable number.

7751380221661 is a deficient number, since it is larger than the sum of its proper divisors (907345571).

7751380221661 is an equidigital number, since it uses as much as digits as its factorization.

7751380221661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907345570.

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 7751380221661 in words is "seven trillion, seven hundred fifty-one billion, three hundred eighty million, two hundred twenty-one thousand, six hundred sixty-one".