21861311683 has 2 divisors, whose sum is σ = 21861311684. Its totient is φ = 21861311682.

The previous prime is 21861311629. The next prime is 21861311701. The reversal of 21861311683 is 38611316812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21861311683 is a prime.

It is not a weakly prime, because it can be changed into another prime (21861381683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10930655841 + 10930655842.

It is an arithmetic number, because the mean of its divisors is an integer number (10930655842).

Almost surely, 2^21861311683 is an apocalyptic number.

21861311683 is a deficient number, since it is larger than the sum of its proper divisors (1).

21861311683 is an equidigital number, since it uses as much as digits as its factorization.

21861311683 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 40.

The spelling of 21861311683 in words is "twenty-one billion, eight hundred sixty-one million, three hundred eleven thousand, six hundred eighty-three".