20864006861 has 2 divisors, whose sum is σ = 20864006862. Its totient is φ = 20864006860.

The previous prime is 20864006851. The next prime is 20864006869. The reversal of 20864006861 is 16860046802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11833305961 + 9030700900 = 108781^2 + 95030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20864006861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20864006869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10432003430 + 10432003431.

It is an arithmetic number, because the mean of its divisors is an integer number (10432003431).

Almost surely, 2^20864006861 is an apocalyptic number.

It is an amenable number.

20864006861 is a deficient number, since it is larger than the sum of its proper divisors (1).

20864006861 is an equidigital number, since it uses as much as digits as its factorization.

20864006861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 110592, while the sum is 41.

The spelling of 20864006861 in words is "twenty billion, eight hundred sixty-four million, six thousand, eight hundred sixty-one".