5661818129 has 4 divisors (see below), whose sum is σ = 6176528880. Its totient is φ = 5147107380.

The previous prime is 5661818089. The next prime is 5661818143. The reversal of 5661818129 is 9218181665.

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.

It is a cyclic number.

It is not a de Polignac number, because 5661818129 - 2²⁴ = 5645040913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5661818179) 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, 257355359 + ... + 257355380.

It is an arithmetic number, because the mean of its divisors is an integer number (1544132220).

Almost surely, 2^5661818129 is an apocalyptic number.

It is an amenable number.

5661818129 is a deficient number, since it is larger than the sum of its proper divisors (514710751).

5661818129 is a wasteful number, since it uses less digits than its factorization.

5661818129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514710750.

The product of its digits is 207360, while the sum is 47.

The square root of 5661818129 is about 75245.0538507349. The cubic root of 5661818129 is about 1782.3184586017.

It can be divided in two parts, 56618 and 18129, that added together give a palindrome (74747).

The spelling of 5661818129 in words is "five billion, six hundred sixty-one million, eight hundred eighteen thousand, one hundred twenty-nine".