21613606740 has 288 divisors, whose sum is σ = 73553380992. Its totient is φ = 5091840000.

The previous prime is 21613606733. The next prime is 21613606741. The reversal of 21613606740 is 4760631612.

It is a happy number.

21613606740 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 3 + 606 + 7 + 40 = 666.

It is a super-2 number, since 2×21613606740² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21613606695 and 21613606704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613606741) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 35962440 + ... + 35963040.

It is an arithmetic number, because the mean of its divisors is an integer number (255393684).

Almost surely, 2^21613606740 is an apocalyptic number.

21613606740 is a gapful number since it is divisible by the number (20) 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 21613606740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36776690496).

21613606740 is an abundant number, since it is smaller than the sum of its proper divisors (51939774252).

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

21613606740 is a wasteful number, since it uses less digits than its factorization.

21613606740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111 (or 1106 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The spelling of 21613606740 in words is "twenty-one billion, six hundred thirteen million, six hundred six thousand, seven hundred forty".