21777777777777 has 16 divisors (see below), whose sum is σ = 33185559768960. Its totient is φ = 12444303975552.

The previous prime is 21777777777757. The next prime is 21777777777893. The reversal of 21777777777777 is 77777777777712.

It is not a de Polignac number, because 21777777777777 - 2⁶ = 21777777777713 is a prime.

21777777777777 is a modest number, since divided by 7777777 gives 2177777 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21777777777693 and 21777777777702.

It is not an unprimeable number, because it can be changed into a prime (21777777777757) 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, 3933502 + ... + 7682967.

It is an arithmetic number, because the mean of its divisors is an integer number (2074097485560).

Almost surely, 2^{21777777777777} is an apocalyptic number.

It is an amenable number.

21777777777777 is a deficient number, since it is larger than the sum of its proper divisors (11407781991183).

21777777777777 is a wasteful number, since it uses less digits than its factorization.

21777777777777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11705752.

The product of its digits is 27682574402, while the sum is 87.

The spelling of 21777777777777 in words is "twenty-one trillion, seven hundred seventy-seven billion, seven hundred seventy-seven million, seven hundred seventy-seven thousand, seven hundred seventy-seven".