21112705252 has 6 divisors (see below), whose sum is σ = 36947234198. Its totient is φ = 10556352624.

The previous prime is 21112705219. The next prime is 21112705253. The reversal of 21112705252 is 25250721112.

It can be written as a sum of positive squares in only one way, i.e., 21029640256 + 83064996 = 145016^2 + 9114^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21112705252.

It is not an unprimeable number, because it can be changed into a prime (21112705253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2639088153 + ... + 2639088160.

Almost surely, 2^21112705252 is an apocalyptic number.

It is an amenable number.

21112705252 is a deficient number, since it is larger than the sum of its proper divisors (15834528946).

21112705252 is a wasteful number, since it uses less digits than its factorization.

21112705252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5278176317 (or 5278176315 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 28.

The spelling of 21112705252 in words is "twenty-one billion, one hundred twelve million, seven hundred five thousand, two hundred fifty-two".