21820680683 has 4 divisors (see below), whose sum is σ = 21821211048. Its totient is φ = 21820150320.

The previous prime is 21820680677. The next prime is 21820680691. The reversal of 21820680683 is 38608602812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21820680683 is a prime.

It is a super-2 number, since 2×21820680683² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21820680653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197753 + ... + 287658.

It is an arithmetic number, because the mean of its divisors is an integer number (5455302762).

Almost surely, 2^21820680683 is an apocalyptic number.

21820680683 is a deficient number, since it is larger than the sum of its proper divisors (530365).

21820680683 is an equidigital number, since it uses as much as digits as its factorization.

21820680683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530364.

The product of its (nonzero) digits is 221184, while the sum is 44.

The spelling of 21820680683 in words is "twenty-one billion, eight hundred twenty million, six hundred eighty thousand, six hundred eighty-three".