20778590447 has 2 divisors, whose sum is σ = 20778590448. Its totient is φ = 20778590446.

The previous prime is 20778590431. The next prime is 20778590453. The reversal of 20778590447 is 74409587702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20778590447 - 2⁴ = 20778590431 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20778590467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10389295223 + 10389295224.

It is an arithmetic number, because the mean of its divisors is an integer number (10389295224).

Almost surely, 2^20778590447 is an apocalyptic number.

20778590447 is a deficient number, since it is larger than the sum of its proper divisors (1).

20778590447 is an equidigital number, since it uses as much as digits as its factorization.

20778590447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3951360, while the sum is 53.

The spelling of 20778590447 in words is "twenty billion, seven hundred seventy-eight million, five hundred ninety thousand, four hundred forty-seven".