2660400161 has 4 divisors (see below), whose sum is σ = 2661284400. Its totient is φ = 2659515924.

The previous prime is 2660400151. The next prime is 2660400167. The reversal of 2660400161 is 1610040662.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1610040662 = 2 ⋅805020331.

It is a cyclic number.

It is not a de Polignac number, because 2660400161 - 2⁶ = 2660400097 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2660400161.

It is not an unprimeable number, because it can be changed into a prime (2660400167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 437591 + ... + 443628.

It is an arithmetic number, because the mean of its divisors is an integer number (665321100).

Almost surely, 2^2660400161 is an apocalyptic number.

It is an amenable number.

2660400161 is a deficient number, since it is larger than the sum of its proper divisors (884239).

2660400161 is an equidigital number, since it uses as much as digits as its factorization.

2660400161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884238.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 2660400161 is about 51579.0670815206. The cubic root of 2660400161 is about 1385.6354586354.

The spelling of 2660400161 in words is "two billion, six hundred sixty million, four hundred thousand, one hundred sixty-one".