21611117272 has 8 divisors (see below), whose sum is σ = 40520844900. Its totient is φ = 10805558632.

The previous prime is 21611117267. The next prime is 21611117273. The reversal of 21611117272 is 27271111612.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611117273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1350694822 + ... + 1350694837.

Almost surely, 2^21611117272 is an apocalyptic number.

It is an amenable number.

21611117272 is a deficient number, since it is larger than the sum of its proper divisors (18909727628).

21611117272 is a wasteful number, since it uses less digits than its factorization.

21611117272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2701389665 (or 2701389661 counting only the distinct ones).

The product of its digits is 2352, while the sum is 31.

Adding to 21611117272 its reverse (27271111612), we get a palindrome (48882228884).

The spelling of 21611117272 in words is "twenty-one billion, six hundred eleven million, one hundred seventeen thousand, two hundred seventy-two".