7961206476721 has 27 divisors (see below), whose sum is σ = 8194443250539. Its totient is φ = 7734553303152.

The previous prime is 7961206476709. The next prime is 7961206476731. The reversal of 7961206476721 is 1276746021697.

It is a happy number.

The square root of 7961206476721 is 2821561.

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., 5739210792225 + 2221995684496 = 2395665^2 + 1490636^2 .

It is not a de Polignac number, because 7961206476721 - 2¹³ = 7961206468529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7961206476731) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 20786439696 + ... + 20786440078.

Almost surely, 2^{7961206476721} is an apocalyptic number.

7961206476721 is the 2821561-st square number.

7961206476721 is the 1410781-st centered octagonal number.

It is an amenable number.

7961206476721 is a deficient number, since it is larger than the sum of its proper divisors (233236773818).

7961206476721 is an frugal number, since it uses more digits than its factorization.

7961206476721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150 (or 575 counting only the distinct ones).

The product of its (nonzero) digits is 10668672, while the sum is 58.

The spelling of 7961206476721 in words is "seven trillion, nine hundred sixty-one billion, two hundred six million, four hundred seventy-six thousand, seven hundred twenty-one".