21661020451106 has 8 divisors (see below), whose sum is σ = 32949157869504. Its totient is φ = 10677967827940.

The previous prime is 21661020451027. The next prime is 21661020451127. The reversal of 21661020451106 is 60115402016612.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76271198630 + ... + 76271198913.

It is an arithmetic number, because the mean of its divisors is an integer number (4118644733688).

Almost surely, 2^{21661020451106} is an apocalyptic number.

21661020451106 is a deficient number, since it is larger than the sum of its proper divisors (11288137418398).

21661020451106 is a wasteful number, since it uses less digits than its factorization.

21661020451106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152542397616.

The product of its (nonzero) digits is 17280, while the sum is 35.

Adding to 21661020451106 its reverse (60115402016612), we get a palindrome (81776422467718).

The spelling of 21661020451106 in words is "twenty-one trillion, six hundred sixty-one billion, twenty million, four hundred fifty-one thousand, one hundred six".