20819773556461 has 16 divisors (see below), whose sum is σ = 22720685068800. Its totient is φ = 18920230529200.

The previous prime is 20819773556453. The next prime is 20819773556531. The reversal of 20819773556461 is 16465537791802.

It is not a de Polignac number, because 20819773556461 - 2³ = 20819773556453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20819773556393 and 20819773556402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20819773551461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 692615250 + ... + 692645308.

It is an arithmetic number, because the mean of its divisors is an integer number (1420042816800).

It is a 1-persistent number, because it is pandigital, but 2⋅20819773556461 = 41639547112922 is not.

Almost surely, 2^{20819773556461} is an apocalyptic number.

It is an amenable number.

20819773556461 is a deficient number, since it is larger than the sum of its proper divisors (1900911512339).

20819773556461 is a wasteful number, since it uses less digits than its factorization.

20819773556461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50720.

The product of its (nonzero) digits is 76204800, while the sum is 64.

The spelling of 20819773556461 in words is "twenty trillion, eight hundred nineteen billion, seven hundred seventy-three million, five hundred fifty-six thousand, four hundred sixty-one".