20818613623 has 8 divisors (see below), whose sum is σ = 21084829200. Its totient is φ = 20553115968.

The previous prime is 20818613617. The next prime is 20818613639. The reversal of 20818613623 is 32631681802.

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-20818613623 is a prime.

It is a super-2 number, since 2×20818613623² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20818613653) 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, 120993 + ... + 237226.

It is an arithmetic number, because the mean of its divisors is an integer number (2635603650).

Almost surely, 2^20818613623 is an apocalyptic number.

20818613623 is a deficient number, since it is larger than the sum of its proper divisors (266215577).

20818613623 is an equidigital number, since it uses as much as digits as its factorization.

20818613623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358961.

The product of its (nonzero) digits is 82944, while the sum is 40.

The spelling of 20818613623 in words is "twenty billion, eight hundred eighteen million, six hundred thirteen thousand, six hundred twenty-three".