21661031332042 has 8 divisors (see below), whose sum is σ = 33611945170500. Its totient is φ = 10457049608544.

The previous prime is 21661031332037. The next prime is 21661031332049. The reversal of 21661031332042 is 24023313016612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19094181956721 + 2566849375321 = 4369689^2 + 1602139^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21661031331989 and 21661031332007.

It is not an unprimeable number, because it can be changed into a prime (21661031332049) 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, 186733028667 + ... + 186733028782.

Almost surely, 2^{21661031332042} is an apocalyptic number.

21661031332042 is a deficient number, since it is larger than the sum of its proper divisors (11950913838458).

21661031332042 is a wasteful number, since it uses less digits than its factorization.

21661031332042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373466057480.

The product of its (nonzero) digits is 31104, while the sum is 34.

Adding to 21661031332042 its reverse (24023313016612), we get a palindrome (45684344348654).

The spelling of 21661031332042 in words is "twenty-one trillion, six hundred sixty-one billion, thirty-one million, three hundred thirty-two thousand, forty-two".