21059212212 has 18 divisors (see below), whose sum is σ = 53233008738. Its totient is φ = 7019737392.

The previous prime is 21059212211. The next prime is 21059212261. The reversal of 21059212212 is 21221295012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17549360676 + 3509851536 = 132474^2 + 59244^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21059212211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 292489023 + ... + 292489094.

Almost surely, 2^21059212212 is an apocalyptic number.

It is an amenable number.

21059212212 is an abundant number, since it is smaller than the sum of its proper divisors (32173796526).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21059212212 is a wasteful number, since it uses less digits than its factorization.

21059212212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584978127 (or 584978122 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 21059212212 in words is "twenty-one billion, fifty-nine million, two hundred twelve thousand, two hundred twelve".