20409278981579 has 2 divisors, whose sum is σ = 20409278981580. Its totient is φ = 20409278981578.

The previous prime is 20409278981561. The next prime is 20409278981591. The reversal of 20409278981579 is 97518987290402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20409278981579 - 2⁸ = 20409278981323 is a prime.

It is not a weakly prime, because it can be changed into another prime (20409278981279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10204639490789 + 10204639490790.

It is an arithmetic number, because the mean of its divisors is an integer number (10204639490790).

Almost surely, 2^{20409278981579} is an apocalyptic number.

20409278981579 is a deficient number, since it is larger than the sum of its proper divisors (1).

20409278981579 is an equidigital number, since it uses as much as digits as its factorization.

20409278981579 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 182891520, while the sum is 71.

The spelling of 20409278981579 in words is "twenty trillion, four hundred nine billion, two hundred seventy-eight million, nine hundred eighty-one thousand, five hundred seventy-nine".