21305205466 has 32 divisors (see below), whose sum is σ = 32442480000. Its totient is φ = 10492701120.

The previous prime is 21305205461. The next prime is 21305205469. The reversal of 21305205466 is 66450250312.

It is not an unprimeable number, because it can be changed into a prime (21305205461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22640556 + ... + 22641496.

It is an arithmetic number, because the mean of its divisors is an integer number (1013827500).

Almost surely, 2^21305205466 is an apocalyptic number.

21305205466 is a deficient number, since it is larger than the sum of its proper divisors (11137274534).

21305205466 is a wasteful number, since it uses less digits than its factorization.

21305205466 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1654.

The product of its (nonzero) digits is 43200, while the sum is 34.

Adding to 21305205466 its reverse (66450250312), we get a palindrome (87755455778).

The spelling of 21305205466 in words is "twenty-one billion, three hundred five million, two hundred five thousand, four hundred sixty-six".