20409278981570 has 16 divisors (see below), whose sum is σ = 36927047777400. Its totient is φ = 8121412568064.

The previous prime is 20409278981561. The next prime is 20409278981579. The reversal of 20409278981570 is 7518987290402.

It is a Cunningham number, because it is equal to 4517663²+1.

It is an interprime number because it is at equal distance from previous prime (20409278981561) and next prime (20409278981579).

It can be written as a sum of positive squares in 4 ways, for example, as 7347336096409 + 13061942885161 = 2710597^2 + 3614131^2 .

It is not an unprimeable number, because it can be changed into a prime (20409278981579) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5287376045 + ... + 5287379904.

Almost surely, 2^{20409278981570} is an apocalyptic number.

20409278981570 is a deficient number, since it is larger than the sum of its proper divisors (16517768795830).

20409278981570 is a wasteful number, since it uses less digits than its factorization.

20409278981570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10574756149.

The product of its (nonzero) digits is 20321280, while the sum is 62.

The spelling of 20409278981570 in words is "twenty trillion, four hundred nine billion, two hundred seventy-eight million, nine hundred eighty-one thousand, five hundred seventy".