21221201104 has 10 divisors (see below), whose sum is σ = 41116077170. Its totient is φ = 10610600544.

The previous prime is 21221201087. The next prime is 21221201117. The reversal of 21221201104 is 40110212212.

It can be written as a sum of positive squares in only one way, i.e., 20807485504 + 413715600 = 144248^2 + 20340^2 .

It is a Harshad number since it is a multiple of its sum of digits (16), and also a Moran number because the ratio is a prime number: 1326325069 = 21221201104 / (2 + 1 + 2 + 2 + 1 + 2 + 0 + 1 + 1 + 0 + 4).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663162519 + ... + 663162550.

It is an arithmetic number, because the mean of its divisors is an integer number (4111607717).

Almost surely, 2^21221201104 is an apocalyptic number.

It is an amenable number.

21221201104 is a deficient number, since it is larger than the sum of its proper divisors (19894876066).

21221201104 is a wasteful number, since it uses less digits than its factorization.

21221201104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326325077 (or 1326325071 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21221201104 its reverse (40110212212), we get a palindrome (61331413316).

The spelling of 21221201104 in words is "twenty-one billion, two hundred twenty-one million, two hundred one thousand, one hundred four".