20819773556481 has 16 divisors (see below), whose sum is σ = 28404136036800. Its totient is φ = 13560684265920.

The previous prime is 20819773556453. The next prime is 20819773556531. The reversal of 20819773556481 is 18465537791802.

It is not a de Polignac number, because 20819773556481 - 2¹⁰ = 20819773555457 is a prime.

It is a super-2 number, since 2×20819773556481² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20819773556081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 381748755 + ... + 381803288.

It is an arithmetic number, because the mean of its divisors is an integer number (1775258502300).

It is a 1-persistent number, because it is pandigital, but 2⋅20819773556481 = 41639547112962 is not.

Almost surely, 2^{20819773556481} is an apocalyptic number.

It is an amenable number.

20819773556481 is a deficient number, since it is larger than the sum of its proper divisors (7584362480319).

20819773556481 is a wasteful number, since it uses less digits than its factorization.

20819773556481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 763552256.

The product of its (nonzero) digits is 101606400, while the sum is 66.

The spelling of 20819773556481 in words is "twenty trillion, eight hundred nineteen billion, seven hundred seventy-three million, five hundred fifty-six thousand, four hundred eighty-one".