21221552105 has 32 divisors (see below), whose sum is σ = 28882694400. Its totient is φ = 14839034112.

The previous prime is 21221552101. The next prime is 21221552119. The reversal of 21221552105 is 50125512212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21221552105 - 2² = 21221552101 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221552101) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3836852 + ... + 3842378.

It is an arithmetic number, because the mean of its divisors is an integer number (902584200).

Almost surely, 2^21221552105 is an apocalyptic number.

It is an amenable number.

21221552105 is a deficient number, since it is larger than the sum of its proper divisors (7661142295).

21221552105 is a wasteful number, since it uses less digits than its factorization.

21221552105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8673.

The product of its (nonzero) digits is 2000, while the sum is 26.

The spelling of 21221552105 in words is "twenty-one billion, two hundred twenty-one million, five hundred fifty-two thousand, one hundred five".