7782591961 has 9 divisors (see below), whose sum is σ = 7955940799. Its totient is φ = 7612946824.

The previous prime is 7782591937. The next prime is 7782591991. The reversal of 7782591961 is 1691952877.

It is a happy number.

The square root of 7782591961 is 88219.

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., 4871342025 + 2911249936 = 69795^2 + 53956^2 .

It is a de Polignac number, because none of the positive numbers 2^k-7782591961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7782591991) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4145355 + ... + 4147231.

Almost surely, 2^7782591961 is an apocalyptic number.

7782591961 is the 88219-th square number.

7782591961 is the 44110-th centered octagonal number.

It is an amenable number.

7782591961 is a deficient number, since it is larger than the sum of its proper divisors (173348838).

7782591961 is an frugal number, since it uses more digits than its factorization.

7782591961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3848 (or 1924 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 55.

The cubic root of 7782591961 is about 1981.7160208368.

The spelling of 7782591961 in words is "seven billion, seven hundred eighty-two million, five hundred ninety-one thousand, nine hundred sixty-one".