20864006447 has 4 divisors (see below), whose sum is σ = 21257667000. Its totient is φ = 20470345896.

The previous prime is 20864006437. The next prime is 20864006489. The reversal of 20864006447 is 74460046802.

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-20864006447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20864006437) 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, 196830197 + ... + 196830302.

It is an arithmetic number, because the mean of its divisors is an integer number (5314416750).

Almost surely, 2^20864006447 is an apocalyptic number.

20864006447 is a deficient number, since it is larger than the sum of its proper divisors (393660553).

20864006447 is an equidigital number, since it uses as much as digits as its factorization.

20864006447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393660552.

The product of its (nonzero) digits is 258048, while the sum is 41.

The spelling of 20864006447 in words is "twenty billion, eight hundred sixty-four million, six thousand, four hundred forty-seven".