21180786613 has 8 divisors (see below), whose sum is σ = 24248570432. Its totient is φ = 18123492096.

The previous prime is 21180786607. The next prime is 21180786667. The reversal of 21180786613 is 31668708112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21180786613 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21180786613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21180786413) 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, 2617995 + ... + 2626072.

It is an arithmetic number, because the mean of its divisors is an integer number (3031071304).

Almost surely, 2^21180786613 is an apocalyptic number.

It is an amenable number.

21180786613 is a deficient number, since it is larger than the sum of its proper divisors (3067783819).

21180786613 is an equidigital number, since it uses as much as digits as its factorization.

21180786613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5244651.

The product of its (nonzero) digits is 96768, while the sum is 43.

The spelling of 21180786613 in words is "twenty-one billion, one hundred eighty million, seven hundred eighty-six thousand, six hundred thirteen".