20878467871 has 2 divisors, whose sum is σ = 20878467872. Its totient is φ = 20878467870.

The previous prime is 20878467847. The next prime is 20878467917. The reversal of 20878467871 is 17876487802.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20878467871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20878467821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10439233935 + 10439233936.

It is an arithmetic number, because the mean of its divisors is an integer number (10439233936).

Almost surely, 2^20878467871 is an apocalyptic number.

20878467871 is a deficient number, since it is larger than the sum of its proper divisors (1).

20878467871 is an equidigital number, since it uses as much as digits as its factorization.

20878467871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8429568, while the sum is 58.

The spelling of 20878467871 in words is "twenty billion, eight hundred seventy-eight million, four hundred sixty-seven thousand, eight hundred seventy-one".