7728140161 has 64 divisors (see below), whose sum is σ = 9813606400. Its totient is φ = 5939122176.

The previous prime is 7728140159. The next prime is 7728140201. The reversal of 7728140161 is 1610418277.

It is a 4-Lehmer number, since φ(7728140161) divides (7728140161-1)⁴.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 7728140161 - 2¹ = 7728140159 is a prime.

It is a super-2 number, since 2×7728140161² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a deceptive number, since it divides R_7728140160.

It is a self number, because there is not a number n which added to its sum of digits gives 7728140161.

It is not an unprimeable number, because it can be changed into a prime (7728140561) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 40042081 + ... + 40042273.

It is an arithmetic number, because the mean of its divisors is an integer number (153337600).

It is a Poulet number, since it divides 2^7728140160-1.

Almost surely, 2^7728140161 is an apocalyptic number.

It is an amenable number.

7728140161 is a deficient number, since it is larger than the sum of its proper divisors (2085466239).

7728140161 is a wasteful number, since it uses less digits than its factorization.

7728140161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438.

The product of its (nonzero) digits is 18816, while the sum is 37.

The square root of 7728140161 is about 87909.8410930198. The cubic root of 7728140161 is about 1977.0834317902.

The spelling of 7728140161 in words is "seven billion, seven hundred twenty-eight million, one hundred forty thousand, one hundred sixty-one".