20820363571 has 18 divisors (see below), whose sum is σ = 25499714940. Its totient is φ = 16903186272.

The previous prime is 20820363569. The next prime is 20820363581. The reversal of 20820363571 is 17536302802.

It is not a de Polignac number, because 20820363571 - 2¹ = 20820363569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20820363571.

It is not an unprimeable number, because it can be changed into a prime (20820363511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4400335 + ... + 4405063.

It is an arithmetic number, because the mean of its divisors is an integer number (1416650830).

Almost surely, 2^20820363571 is an apocalyptic number.

20820363571 is a deficient number, since it is larger than the sum of its proper divisors (4679351369).

20820363571 is an frugal number, since it uses more digits than its factorization.

20820363571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9491 (or 4755 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 20820363571 in words is "twenty billion, eight hundred twenty million, three hundred sixty-three thousand, five hundred seventy-one".