5661531335021 has 4 divisors (see below), whose sum is σ = 5856756553500. Its totient is φ = 5466306116544.

The previous prime is 5661531335011. The next prime is 5661531335027. The reversal of 5661531335021 is 1205331351665.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2609068098121 + 3052463236900 = 1615261^2 + 1747130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5661531335021 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 5661531335021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5661531335027) 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, 97612609196 + ... + 97612609253.

It is an arithmetic number, because the mean of its divisors is an integer number (1464189138375).

Almost surely, 2^{5661531335021} is an apocalyptic number.

It is an amenable number.

5661531335021 is a deficient number, since it is larger than the sum of its proper divisors (195225218479).

5661531335021 is a wasteful number, since it uses less digits than its factorization.

5661531335021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195225218478.

The product of its (nonzero) digits is 243000, while the sum is 41.

Adding to 5661531335021 its reverse (1205331351665), we get a palindrome (6866862686686).

The spelling of 5661531335021 in words is "five trillion, six hundred sixty-one billion, five hundred thirty-one million, three hundred thirty-five thousand, twenty-one".