21136311623 has 8 divisors (see below), whose sum is σ = 24270268800. Its totient is φ = 18030975480.

The previous prime is 21136311601. The next prime is 21136311629. The reversal of 21136311623 is 32611363112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21136311623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21136311629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7153673 + ... + 7156626.

It is an arithmetic number, because the mean of its divisors is an integer number (3033783600).

Almost surely, 2^21136311623 is an apocalyptic number.

21136311623 is a deficient number, since it is larger than the sum of its proper divisors (3133957177).

21136311623 is a wasteful number, since it uses less digits than its factorization.

21136311623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14310517.

The product of its digits is 3888, while the sum is 29.

Adding to 21136311623 its reverse (32611363112), we get a palindrome (53747674735).

The spelling of 21136311623 in words is "twenty-one billion, one hundred thirty-six million, three hundred eleven thousand, six hundred twenty-three".