21263505212 has 6 divisors (see below), whose sum is σ = 37211134128. Its totient is φ = 10631752604.

The previous prime is 21263505181. The next prime is 21263505217. The reversal of 21263505212 is 21250536212.

21263505212 is nontrivially palindromic in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21263505217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2657938148 + ... + 2657938155.

It is an arithmetic number, because the mean of its divisors is an integer number (6201855688).

Almost surely, 2^21263505212 is an apocalyptic number.

It is an amenable number.

21263505212 is a deficient number, since it is larger than the sum of its proper divisors (15947628916).

21263505212 is a wasteful number, since it uses less digits than its factorization.

21263505212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5315876307 (or 5315876305 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The spelling of 21263505212 in words is "twenty-one billion, two hundred sixty-three million, five hundred five thousand, two hundred twelve".