21136311624 has 64 divisors (see below), whose sum is σ = 54828311040. Its totient is φ = 6782791680.

The previous prime is 21136311601. The next prime is 21136311629. The reversal of 21136311624 is 42611363112.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21136311591 and 21136311600.

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 15 ways as a sum of consecutive naturals, for example, 69994 + ... + 217190.

It is an arithmetic number, because the mean of its divisors is an integer number (856692360).

Almost surely, 2^21136311624 is an apocalyptic number.

21136311624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21136311624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27414155520).

21136311624 is an abundant number, since it is smaller than the sum of its proper divisors (33691999416).

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

21136311624 is a wasteful number, since it uses less digits than its factorization.

21136311624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147430 (or 147426 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

Adding to 21136311624 its reverse (42611363112), we get a palindrome (63747674736).

The spelling of 21136311624 in words is "twenty-one billion, one hundred thirty-six million, three hundred eleven thousand, six hundred twenty-four".