21111280272 has 120 divisors (see below), whose sum is σ = 63889053696. Its totient is φ = 6482193408.

The previous prime is 21111280259. The next prime is 21111280283. The reversal of 21111280272 is 27208211112.

It is a happy number.

21111280272 is a `hidden beast` number, since 2 + 1 + 111 + 280 + 272 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23313 + ... + 206799.

Almost surely, 2^21111280272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111280272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31944526848).

21111280272 is an abundant number, since it is smaller than the sum of its proper divisors (42777773424).

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

21111280272 is a wasteful number, since it uses less digits than its factorization.

21111280272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183565 (or 183556 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

Adding to 21111280272 its reverse (27208211112), we get a palindrome (48319491384).

The spelling of 21111280272 in words is "twenty-one billion, one hundred eleven million, two hundred eighty thousand, two hundred seventy-two".