20178448889 has 2 divisors, whose sum is σ = 20178448890. Its totient is φ = 20178448888.

The previous prime is 20178448847. The next prime is 20178448897. The reversal of 20178448889 is 98884487102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19734630400 + 443818489 = 140480^2 + 21067^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20178448889 is a prime.

It is not a weakly prime, because it can be changed into another prime (20178448489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10089224444 + 10089224445.

It is an arithmetic number, because the mean of its divisors is an integer number (10089224445).

Almost surely, 2^20178448889 is an apocalyptic number.

It is an amenable number.

20178448889 is a deficient number, since it is larger than the sum of its proper divisors (1).

20178448889 is an equidigital number, since it uses as much as digits as its factorization.

20178448889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8257536, while the sum is 59.

The spelling of 20178448889 in words is "twenty billion, one hundred seventy-eight million, four hundred forty-eight thousand, eight hundred eighty-nine".