7840161281 has 16 divisors (see below), whose sum is σ = 8204541840. Its totient is φ = 7482558720.

The previous prime is 7840161253. The next prime is 7840161293. The reversal of 7840161281 is 1821610487.

It is a happy number.

7840161281 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 24010000 + 7816151281 = 4900^2 + 88409^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7840161281 is a prime.

It is a super-2 number, since 2×7840161281² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7840161181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 892571 + ... + 901311.

It is an arithmetic number, because the mean of its divisors is an integer number (512783865).

Almost surely, 2^7840161281 is an apocalyptic number.

It is an amenable number.

7840161281 is a deficient number, since it is larger than the sum of its proper divisors (364380559).

7840161281 is a wasteful number, since it uses less digits than its factorization.

7840161281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9124.

The product of its (nonzero) digits is 21504, while the sum is 38.

The square root of 7840161281 is about 88544.6852216439. The cubic root of 7840161281 is about 1986.5903989903.

The spelling of 7840161281 in words is "seven billion, eight hundred forty million, one hundred sixty-one thousand, two hundred eighty-one".