21243525212 has 24 divisors (see below), whose sum is σ = 45755285856. Its totient is φ = 8404031808.

The previous prime is 21243525209. The next prime is 21243525271. The reversal of 21243525212 is 21252534212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29180303 + ... + 29181030.

It is an arithmetic number, because the mean of its divisors is an integer number (1906470244).

Almost surely, 2^21243525212 is an apocalyptic number.

It is an amenable number.

21243525212 is an abundant number, since it is smaller than the sum of its proper divisors (24511760644).

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

21243525212 is a wasteful number, since it uses less digits than its factorization.

21243525212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58361357 (or 58361355 counting only the distinct ones).

The product of its digits is 9600, while the sum is 29.

The spelling of 21243525212 in words is "twenty-one billion, two hundred forty-three million, five hundred twenty-five thousand, two hundred twelve".