6331531533661 has 4 divisors (see below), whose sum is σ = 6402672337500. Its totient is φ = 6260390729824.

The previous prime is 6331531533631. The next prime is 6331531533673. The reversal of 6331531533661 is 1663351351336.

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 627406568100 + 5704124965561 = 792090^2 + 2388331^2 .

It is a cyclic number.

It is not a de Polignac number, because 6331531533661 - 2⁹ = 6331531533149 is a prime.

It is a super-2 number, since 2×6331531533661² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6331531533631) 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, 35570401786 + ... + 35570401963.

It is an arithmetic number, because the mean of its divisors is an integer number (1600668084375).

Almost surely, 2^{6331531533661} is an apocalyptic number.

It is an amenable number.

6331531533661 is a deficient number, since it is larger than the sum of its proper divisors (71140803839).

6331531533661 is an equidigital number, since it uses as much as digits as its factorization.

6331531533661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71140803838.

The product of its digits is 1312200, while the sum is 46.

Adding to 6331531533661 its reverse (1663351351336), we get a palindrome (7994882884997).

The spelling of 6331531533661 in words is "six trillion, three hundred thirty-one billion, five hundred thirty-one million, five hundred thirty-three thousand, six hundred sixty-one".